In my 9-17 life, I am behind a corporate firewall with semi-restrictive content filtering. This usually does not bother me; It is only fair that only job-related surfing is done from work. And when it does get in the way of a job-related need, I whine a bit and find a way to get things done.
I noticed recently that our proxy blocks twitter but allows facebook. At first I thought this was weird - is facebook more safe or more needed for bankers to do their job? I thought not.
But after thinking some more I think I understand how this can make sense.
On facebook, I am only connected to people that I know or at least used to know. On twitter, I follow several people that I don't know at all except from their tweets and blogs.
My facebook friends don't publish many links - mostly just status updates, pictures and the occational youtube video. Twitter on the other hand is overflowing with links, most of them shortened so you can't see what site they link to before it's too late.
In addition to following people on twitter, the search feature makes it easy to follow topics. (I use TweetDeck for this.) That means that I can interact with even more people I don't know. This raises the risk of social engineering. (I of course think myself impervious to such stunts, but some of my collegues could be vulnerable :-).
As a service or a platform in itself, I would still maintain that facebook carries a greater risk because facebook apps could do be serving nasty content, and most apps require access to profile information that is not needed for the app. Thankfully facebook is moving away from this pattern, but ill-intended apps would of course continue to ask for full profile access just to complete a quiz, and many users will continue to grant it.
So in the end I wonder: Someone thought about this and decided to block twitter. Why did they leave facebook open?