Archive for November, 2007

Whatsoever u say, i trust u because u r my friend

Thursday, November 29th, 2007

Say that in the near future you will be able to post a question on social network sites. You will get many different answers (whose quality may vary). It would be nice if you could get a list of answers ranked by quality.

Problem: how to rank answers? That’s a cool problem that is disappointingly hard to solve.

Some would argue for using social networks – people close to you should be trusted and they can surely answer any type of question. For me, that’s hard to believe. That is probably because my friends have diverging interests (a few know about technology or finance, a handful of them knows about literature, and many about architecture and design – I have a weakness for creative people). And they also think differently – I’m fortunate enough to have few friends who are left-brainers, while most of them go for the “right” side. If many people would go along with my personal experience, then we could deem those solutions oversimplified at best.

So how to go about the initial problem? For a start, I would acknowlege that:
a) “X befriends Y” and “X trusts Y” are two totally different concepts. I’m overemphasizing by saying “totally”: after all, there may be a correlation between the two concepts; but it is difficult to buy into the causation arrow “I befriend you” -> “I trust you”. Therefore, that distinction may be important (if not crucial), and we usually underemphasize it “for simplicity’s sake”.
b) “X trusts Y” has little meaning. Since trust is context dependent (1, 2, 3), one needs to specify for what X trusts Y. X may trust Y for academic tips but not for real-world issues ;-). So a better way could be “X trusts Y for doing Z”, and that Z would be crucial.

Given these two points, I really like this recent paper. The authors separate social networks and webs of trust (which they call vote-on networks), and they are planning to build around context-specific webs of trust. Great work!

2nd of March: Social Software & Portability

Wednesday, November 28th, 2007

The fact that there are so many companies allegedly going open  shows that portability of social networks is an open and important issue. There will be a “Social Network Portability” workshop (co-located with BlogTalk – 5th Int. Conference on Social Software) in Cork, Ireland on the 2nd March 2008. Its goal is to discuss all aspects of portability for social networking sites (including accounts, friends, activities / content, and applications).

Are you downloading copyrighted files? You are out!

Tuesday, November 27th, 2007

A proposal(*) backed by French president Nicolas Sarkozy: those people who download copyrighted material (using, for example, P2P networks) will get disconnected from the Internet by their ISPs.

“Like it or not, the total cost of Internet service will rise because French ISPs have signed on to the plan. They will now spend time and (tax) money enforcing copyright on their networks via expensive deep packet inspection (DPI) software that will monitor traffic on their networks and look for copyrighted content. Subscribers detected illicitly sharing or downloading copyrighted material will receive warnings, requiring additional administrative overhead. If the behavior continues, then Internet access would be guillotined. Most of this will be carried out by a government-funded independent authority overseen by a judge” (full post).

(*) I do not describe the proposal as being insane just for this reason: “Do not be hectoring or arrogant. Those who disagree with you are not necessarily stupid or insane. Nobody needs to be described as silly: let your analysis show that he is. When you express opinions, do not simply make assertions. The aim is not just to tell readers what you think, but to persuade them; if you use arguments, reasoning and evidence, you may succeed. Go easy on the oughts and shoulds. ” You may well understand to which category Mr. Sarkozy qualifies to belong.

Mobblog. One Year.

Sunday, November 25th, 2007

In these days, this blog is celebrating its first birthday since being revived from oblivion. One of the natural things to think about is how useful it has been to everybody- not just those actively posting and commenting (thus revealing their identity), but also the quiet anonymous readers and the members of our research group and community.

This has been an ongoing discussion, but we are interested in hearing from everybody. Therefore, we have made a short survey where anyone can leave feedback/thoughts/comments. Tell us what you like, what you don’t like, what you would like to see, or what should be removed. Feel free to be as harsh or nice as you want. Please take 2 minutes to answer the survey questions here.

Recommendation or Spam?!

Thursday, November 22nd, 2007

As part of my PhD I am interested in investigating the effect of spam in pub-sub and how to use social networks to minimize amount of delivered spam in MANETs. Recently I came across an article about Facebook starting their ‘Social Advertising‘. The idea is putting your face on advertisements for products that you like.

For example, a Facebook user who rents a movie on will be asked if he would like to have his movie choice broadcast out to all his friends on Facebook. And those friends would have no Microsoft Office Home Business 2013 best price choice but to receive that movie message, along with an ad from Blockbuster.

Facebook says that many of its 50 million active users already tell friends about particular products or brands they like, and the only change will be that those communications might start to carry ad messages from the companies that sell them. Facebook is letting advertisers set up their own profile pages at no charge and encouraging companies like Blockbuster, Conde Nast and Coca-Cola to share information with Facebook about the actions of Facebook members on their sites.

Facebook users will not be able to avoid these personally recommended ads if they are friends with participating people. Participation can involve joining a fan club for a brand, recommending a product or sharing information about their purchases from external Web sites.

Although I agree the idea of sharing information with your friends is very useful but at the same time it can potentially create too much spam. So the question is that, are recommendations going to be new labels for spamming?

You can find the main article by Louise Story in here

Online Identity

Wednesday, November 21st, 2007

I was reading this interesting article on comment trolling on blogs. It breaks down people order generic cialis who comment on blogs into three categories; those who read and comment with something useful to say, those who “spam”-comment, hoping to generate traffic for their own web sites, and the trolls: those who comment to criticise/put down both the content and the authors (luckily (?) it seems that mobblog has very few of the first category and no trolls!). The interesting thing about the article was the pointer to this other one, which explains that this destructive behaviour may be explained by the lack of online identiy. Here is a quote from the article: (more…)

Visualization tool for data-sets

Friday, November 16th, 2007

This is something I found while looking for social networking datasets:
Many Eyes” has range of different datasets( e.g. facebook, secondlife, etc) and also provides users with different styles of visualizations. I guess it is quite useful when you want to visualize a small dataset (fraction of traces) without the need of coding visualization parts.

Crowdsourcing traffic information

Friday, November 16th, 2007

“You’re sitting in a traffic jam, late for a meeting, watching the estimated time of arrival on your satnav’s display creep later and later as it takes account of the fact that, right now, you’re not going anywhere. Do you cancel, try another route, or wait it out?

TomTom, the Dutch maker of navigation devices, is claiming to put an end to this kind of dilemma with a new service it launched today in the Netherlands, dubbed High Definition Traffic. It tracks the paths of about 4 million Vodafone mobile phone users to expand the amount of traffic information available“. More on FT’s tech blog.

Measurement and Analysis of Online Social Networks

Wednesday, November 14th, 2007

At IMC, it has been presented the first study to examine multiple online social networks at scale. The paper analyzes “data gathered from four popular online social networks: Flickr, YouTube, LiveJournal, and Orkut”.


  • “the indegree of user nodes tends to match the outdegree;
  • the networks contain a densely connected core of high-degree nodes;
  • this core links small groups of strongly clustered, low-degree nodes at the fringes of the network”.

Implications on info dissemination and search

  • “The existence of a small, well-connected core implies that information seeded via a core node will rapidly spread through the entire network.”
  • “Similarly, searches that proceed along social network links will quickly reach the core. This suggests that simple unstructured search algorithms could be designed if the core users were to store some state about other users.”

Implications on trust
“In a social network, the underlying user graph can potentially be used as a means to infer some level of trust in an unknown user, to check the validity of a public key certificate, and to classify potential spam”.

  • “The tight core coupled with link reciprocity implies that users in the core appear on a large number of short paths. Thus, if malicious users are able to penetrate the core, they can skew many trust paths (or appear highly trustworthy to a large fraction of the network).”
  • “However, these two properties also lead to small path lengths and many disjoint paths, so the trust inference algorithms should be adjusted to account for this observation. In particular, given our data, an unknown user should be highly trusted only if multiple short disjoint paths to the user can be discovered.”
  • “The correlation in link degrees implies that users in the fringe will not be highly trusted unless they form direct links to other users. The “social” aspect of these networks is selfreinforcing: in order to be trusted, one must make many “friends”, and create many links that will slowly pull the user into the core.”

A World Wide Web Without Walls

Tuesday, November 13th, 2007

This paper by MIT folks puts forward W5 – A World Wide Web Without Walls: “This paper imagines a very different Web ecosystem, in which users retain control of their data and developers can justify their existence without hoarding that data”

Compare that to what Ross Anderson wrote in 2002: “Information security is about money and power; it’s about who gets to read, write, or run which file. The economics of information goods and services markets is dominated by the establishment and defence of monopolies, the manipulation of switching costs, and the control of interoperability.”

Given the sad reality, W5 will have to rely not only on sound tech design but also on good luck.

To be Levy, or not to be: that is the question

Tuesday, November 13th, 2007

Last month, Science published this paper: “Our results question the strength of the empirical evidence for biological Levy flights.”

People have been developing theoretical models assuming Levy flights for twenty years now.

But, no worries, seems to suggest this paper currently discussed at HotNets: “We conduct a statistical study of human mobility… Our data reveals statistical features similar to those in what physicists have long called Levy random walks (or Levy walks).”

Physicists have long called them so, but they have apparently just stopped. How much more confusing can it get?

P.S. In the Science paper, consider also the allure of Box 1 exotically titled “When is a power law not a power law?”

DelFly: Tiny Robotic Ornithopter Spy

Saturday, November 3rd, 2007

BoingBoing has a video of a tiny camera-carrying ornithopter developed at the Delft University of Technology. The ornithopter has a 35 cm wingspan and can carry a camera and video transmitter for 17 minutes. The next model will have a 10 cm wingspan.

As usual, the researcher “suggests that it could be used to locate victims in collapsed buildings”. If that happens before they’re used for police surveillance or military targetting, I’ll be pleasantly surprised.