Josh Wolf, the blogger whose record 7 1/2 months in federal prison stirred debate about who qualifies as a journalist and what legal protections journalists should receive, was freed Tuesday after releasing video footage sought by prosecutors about an anarchist protest.

Wolf, 24, held in contempt by a federal judge last August for defying a grand jury subpoena, walked out of the federal prison in Dublin at mid-afternoon after his lawyers and federal prosecutors reached a compromise during a mediation session Monday before a federal magistrate.  Wolf posted the uncut video on his Web site, gave prosecutors a copy and denied under oath that he knew anything about violent incidents at the July 2005 protest. In return, his lawyers said, prosecutors agreed not to summon him before the grand jury or ask him to identify any of the protesters shown on his video. Prosecutors’ withdrawal of their demand for his testimony was the key to the deal, Wolf said outside the prison gate. “Journalists absolutely have to remain independent of law enforcement,” he said. “Otherwise, people will never trust journalists.”

He said later that he had offered to turn over his videos last November on the condition that he be excused from testifying, but prosecutors turned him down. U.S. Attorney Scott Schools’ office did not respond to a reporter’s question about why prosecutors accepted those conditions Tuesday.

Asked about his imprisonment — the longest-ever for a U.S. journalist for withholding information — Wolf said, “Absolutely, this was worth it. I would do it again if I had to.” He also said his case showed the need for a federal shield law that would protect journalists, including bloggers, from having to disclose confidential sources or unpublished material.

California and most other states have shield laws, but they do not apply to proceedings in federal court.