Update: An earlier version of this story misspelled the name of the hacker group Rustle League. It also said that the group involved was Russian, which is not the case. We apologise for the error.
On Twitter, it turns out nobody's safe: the hacking collective Anonymous has had one of its accounts taken over by a rival group.
The account @Anon_Central, which has 165,000 followers, is one of several which act as news and action feeds for the group.
But on Thursday it was successfully hacked by the hacking group Rustle League.
The group posted:
The admins of @Anon_Central eventually recovered control of the account - presumably changing its password to something a bit more secure.
The attack comes after a week of high-profile hacks on Twitter.
Accounts belonging to Burger King, Jeep, Donald Trump and Jeremy Clarkson have all been targeted in recent days.
Twitter has since reminded its users to change their passwords frequently, use a mix of upper and lower caps letters, symbols and numbers, and to watch out for suspicious links on its site.
"Over the past couple of days, there's been a fair amount of conversation about account security on Twitter. We thought we'd take advantage of this moment to remind you of best practices around passwords...
"Use a strong password.. Watch out for suspicious links, and always make sure you're on Twitter.com before you enter your login information.. Don't give your username and password out to unknown third parties.. Make sure your computer and operating system is up to date with the most recent patches, upgrades, and anti-virus software"
Twitter has also implemented a new security feature to make sure its users won't see emails pretending to be from Twitter.com.
"Without getting too technical, DMARC solves a couple of long-standing operational, deployment, and reporting issues related to email authentication protocols. It builds on established authentication protocols (DKIM and SPF) to give email providers a way to block email from forged domains popping up in inboxes."