Actually, censorship is nothing new for Turkey so some serious portion of the population knows how to overcome it. Probably these tweets are sent mostly by Turks in Turkey :)
However, this is not the whole story. The current ruling party has huge support from the uneducated and/or religious masses that may not be that informed about the technology. Since 3 months new corruption documents are leaked through twitter, which puts pressure on the PM. Just yesterday there was a phone conversation of one of the Ministers leaked and apparently the guy was mocking Islam when he was trying to look like as devoted muslim in front of the public.
However, this is not the whole story. The current ruling party has huge support from the uneducated and/or religious masses that may not be that informed about the technology. Since 3 months new corruption documents are leaked through twitter, which puts pressure on the PM. Just yesterday there was a phone conversation of one of the Ministers leaked and apparently the guy was mocking Islam when he was trying to look like as devoted muslim in front of the public.