The Guardian journalist Jack Shenker was beaten and brutalized by Egypt's state security service.  He wrote an article here detailing his experience.

Shenker has confirmed what the West has long suspected: Egypt's heavy-handed regime is responding to the protests with brutal violence.

 

Upon fleeing the scene of a protest and stopping at what he judged to be a safe distance, he was jumped by a few amin dowla, Egypt's plainclothes state security officers.

 

They beat him and slapped him despite his repeated statement -- in Arabic and English -- that he was a British journalist.

 

Shenker (along with other rounded-up protesters) was then taken to a security office and beaten some more. His cell phone and wallet were then confiscated. 

 

Shenker was eventually released. However, he was immediately met with more police officers with riot shields and got herded into a green truck. 

 

As the truck, packed with protesters, began to move, someone said to him: what you see here – this brutality and torture – this is why we were protesting today.

 

After a long ride, the protesters packed inside noticed some commotion outside. The truck's door finally opened and Shenker gained his freedom.  He and others protesters, stranded miles outside of Cairo, then made their long journey back.

 

Later, Shenker found out his truck was freed by the father of one of the captured protesters, who fought with police officers for their release.