The hacker-activist group Anonymous says it hijacked the website of the U.S. Sentencing Commission to avenge the death of Aaron Swartz, an Internet activist who committed suicide.

The website of the commission, an independent agency of the judicial branch, was taken over early Saturday and replaced with a message warning that when Swartz killed himself two weeks ago “a line was crossed.”

The hackers said they have infiltrated several government computer systems and copied secret information that they now threaten to make public.

In a message posted on the homepage of the hacked website, Anonymous claimed the Federal Bureau of Investigation had "infiltrated" their group last year.

"As a result of the FBI's infiltration and entrapment tactics, several more of our brethren now face similar disproportionate persecution, the balance of their lives hanging on the severely skewed scales of a broken justice system," the message read.

Family and friends of Swartz, who helped create Reddit and RSS, said he killed himself after he was hounded by federal prosecutors. Officials said he helped post millions of court documents for free online and that he illegally downloaded millions of academic articles from an online clearinghouse.

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