Wednesday 6 November 2013

Graduated again

In September I graduated again, this time from the Faculty of Computer and Information Science of the University of Ljubljana. My graduation thesis, "Analysis of Slovenian politics activity on Twitter" (in Slovenian "Analiza slovenskega političnega prostora na Twitterju") is available on-line and the code used to get the data is available on github.
In my thesis I analysed the Slovenian political activity on Twitter, both on a party and on a deputy level. I tried to find a correlation between election results, activity (tweets per day), number of tweets and number of followers, the lexical diversity of words, hashtags and mentions used in tweets and the connections between the followers and the parties/deputies.
While researching the connections I created a few maps of Slovenian politics on Twitter. The first one depicts the parties (coloured circles) and their followers (grey circles).
The second map is similar, but this time it shows deputies (same colour as their parties). instead of parties.
The other maps show only the followers of the deputies from the same party. You'll find there's no maps for two parties, as one has only one tweeting deputy and the other one doesn't have a connection between the two tweeting deputies.
DL deputies
NSi deputies
PS deputies
SD deputies

SDS deputies
I generated the graphs using the code available on github and the pictures using Gephi.

Wednesday 6 February 2013

An A Song of Ice and Fire network

This post contains spoilers for both the book series A Song of Ice and Fire and the TV show Game of Thrones.
For a school project we had to create a network, so I decided I'd create an ASOIAF network starting from Ned. Using A Wiki of Ice and Fire and Gephi, I created a network with characters as nodes and their relationships as edges. The relationships I used were spouses, siblings and parent-child.

As can be seen from the network graph, most of the great houses are connected. In fact, only the Greyjoys are missing.

I'm including the .gephi file as well as a .gml file if anyone would like to play with the data.
Gephi file
GML file

Edit: Added Walder Frey's bastard children

Tuesday 5 February 2013

Facebook photos privacy

If you are a facebook user, you might have seen posts that go something like this
"I enjoy my privacy so please make a few clicks so if you like my status/pictures/whatever, they won't show on your friends' walls."
This works well with status updates (though it's pretty stupid that we need to do that and how can you be sure that all of your friends will do that or that facebook won't just change the privacy settings again?), but there's a problem with the photos you upload. While this method will hide them from your friends' friends, they are not 100% safe from strangers. Let me elaborate on that.
If you take the url to a photo in a facebook gallery, like this for example http://www.facebook.com/photo.php?fbid=10151265478032446&set=a.10151214746012446.480779.679047445&type=3&theater, only my friends will be able to see it. But if you take the direct URL of the picture (right click on picture -> show image or something like that) you get a URL like this http://sphotos-b.ak.fbcdn.net/hphotos-ak-ash4/311217_10151265478032446_2030697084_n.jpg, you can give it to anyone and they can see the photo. As you can see, the name of the picture is made out of three numbers separated by an underscore, with the middle number representing the picture id. Here's a few more examples:
http://sphotos-d.ak.fbcdn.net/hphotos-ak-ash3/60675_10151201144402446_161978646_n.jpg
http://sphotos-f.ak.fbcdn.net/hphotos-ak-snc6/223340_10151217072382446_1638752273_n.jpg
http://sphotos-e.ak.fbcdn.net/hphotos-ak-ash3/58367_10151201145747446_1713269601_n.jpg
http://sphotos-b.ak.fbcdn.net/hphotos-ak-snc7/314234_10151219854077446_1301291355_n.jpg
http://sphotos-d.ak.fbcdn.net/hphotos-ak-snc6/269560_10150260576312446_7947755_n.jpg
http://sphotos-a.ak.fbcdn.net/hphotos-ak-prn1/25160_383525892445_8208924_n.jpg
https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-ash3/644233_407306429357603_1603733801_n.jpg
(The last one is actually not mine, but I needed it to make a point)
As you can see, the photos are saved at two other locations, fbcdn.net and akamaihd.net. From the given examples it shouldn't be too hard to write a small program that checks all the combinations and downloads the photo, if it finds it. Now, you can't target a specific user, as the user id isn't present in the URL, but it's still scary that getting ALL the photos on facebook is just a few minutes of coding away (not sure how legal it is though).
In conclusion, treat your data on facebook like a blog: everyone can see it, but only a few people actually will.

Friday 1 February 2013

Dusting off this blog

It's been quite a while since I posted anything here. I have a couple of ideas and projects that I want to do, that I'm going to write about in the future, so hopefully I'll be more active here.