Rami Samara, an editor at the official Palestinian news agency Wafa, said plainclothes security agents took him from his office to Abbas' headquarters on Tuesday and held him for four hours. They showed me about 100 pages of comments I made on Facebook, mostly criticizing the Palestinian Authority and the PLO, he said.

He said he was told he would be released if he signed a confession that he organized an anti-government demonstration on behalf of a small PLO faction critical of Abbas. Samara said he refused, but he was eventually released.

Before this detention, I thought that we, the Palestinian people, enjoy wide freedom, but after what I saw, I think I'm being followed by the intelligence in every step of my life, he said.

Abbas' office did not respond to requests for comment.

In another case, journalist Yousef Shayeb, who writes for the Jordanian newspaper al-Ghad, said he was held for eight hours at a Palestinian intelligence office Tuesday. He said he was questioned about stories in which he alleged a Palestinian diplomatic mission abroad was riddled by corruption. Shayeb said interrogators demanded that he reveal his sources, which he said he refused to do.