Because they are on a big brother protect the innocent trip and a monopoly push- plain and simple.
I still cannot get why flickr is blocked - a lot of my friends and family post pics there that i would like to see.
The thing is if i wanted to look at p0rn there are a lot better places then flickr to go
I would not suprise me if soon they release there own crumby coded photo sharing site - and collect the ad revenue for themselves.