Social media accounts belonging to the NFL and several of its teams, including the Buffalo Bills and Green Bay Packers, were hacked on Monday.
In a since-deleted tweet on the official league account, a group calling itself OurMine said the account had been taken over.
“Hi, we’re Back (OurMine). We are here to Show people that everything is hackable,” it read, adding contact information “to improve you accounts security.”
The same message was posted on the league’s Facebook account, and those of the Buffalo Bills and Houston Texans, according to USA Today. The posts were later deleted.
The Green Bay Packers’ Twitter account also fell prey, as did the Cleveland Browns and Arizona Cardinals. The Instagram page for the Minnesota Vikings was also hacked.
Several of the teams’ Twitter profile pictures also appeared to have been briefly deleted.
The same group hacked the Chicago Bears account on Sunday and announced that the team had been sold to Saudi Arabia official Turki Al-Sheikh, according to NBC Chicago.
That tweet was quickly followed up by an explanation from OurMine saying the page had been hacked “1) Announce that we are back…2) Show people that everything is hackable.”
A Twitter spokeswoman confirmed the accounts had been hacked.
“As soon as we were made aware of the issue, we locked the compromised accounts and we are currently investigating the situation,” Jen Santamaria said.
The NFL didn’t immediately respond to a request for comment.