An American journalist has been found guilty of helping hacktivist group Anonymous deface the website of the Los Angeles Times.

Prosecutors said Matthew Keys, 28, provided the hackers a password to access systems belonging to Tribune Co, the newspaper's parent company.

Prosecutors said Keys used online chat channels to encourage the hacktivists.

Sentencing will take place in January, but he is not expected to receive the maximum possible sentence of 25 years.

A spokesman for the US Justice Department told Reuters the sentence would likely be less than five years.

Keys' lawyer said he planned to appeal the verdict.

Keys was charged with conspiracy to cause damage to a protected computer, transmission of malicious code, and attempted transmission of malicious code. He was found guilty on all three counts.

Court documents said the incidents took place in December 2010, shortly after Keys had lost his job at California-based TV station Fox 40 KTXL, also owned by Tribune Co.

Keys went on to work for Reuters as the agency's social media editor, but was let go after he was charged in 2012.

'Elect Chippy 1337'

Prosecutors said Keys' actions were "anonymous revenge".

Under the online pseudonym AESCracked, Keys was said to have shared log-in details for the LA Times' content management system - CMS - the software used to enter content, such as articles or pictures, to be published on the newspaper's website.

With this information, an unidentified Anonymous member using the name "sharpie" is said to have edited a story on the LA Times site.

A headline was altered to read: "Pressure builds in House to elect CHIPPY 1337".

Within the article, the opening paragraph was also changed to include the phrase "reluctant House Democrats told to SUCK IT UP".

The defacement was "live" on the LA Times site for about an hour, the defence said.

Tribune Co said it cost at least $5,000 to fix and investigate the incident which, as Vice's technology site Motherboard points out, is the threshold amount for being able to bring charges under the Computer Fraud and Abuse Act.

A spokesman for Tribune Co, Gary Weitman, said: "We are pleased that the justice system worked. We will let today's verdict speak for itself."

Media sites targeted

Anonymous, a loosely organised group of mostly low-level hackers, often targeted mainstream media websites and social media profiles.

One splinter group Lulzsec took credit for posting a story to The Sun's website stating that its owner, Rupert Murdoch, had committed suicide.

In another instance, on the website for US broadcaster PBS, a story was posted saying that rapper Tupac Shakur, who was shot and killed in 1996, was in fact alive and living in New Zealand.

Key members of Lulzsec were arrested after hacker-turned-informant Hector Xavier Monsegur - known as Sabu - helped police establish real identities behind the hackers.

As a result, Monsegur was given a reduced sentence of one year under supervision.

Source: BBC