It’s no laughing matter.

A hacking group that calls itself the “Chuckling Squad” has been waging a cyber campaign against the rich and famous, inducing “Kick Ass” star Chloë Grace Moretz and Twitter CEO Jack Dorsey, in which they break into victims’ phones and use their Twitter accounts to broadcast racial slurs and internet jokes.

Dorsey, 42, had his own personal Twitter account hijacked on Aug. 30, an irony internet wags found hilarious. Brooklyn rapper Joey Bada$$ also had his Twitter hacked Wednesday; it’s unclear if it was the work of the same group.

Dorsey’s and Moretz’s accounts were taken over with a service Twitter owns, called Cloudhopper, that allows users to tweet via SMS messages. Twitter blamed Dorsey’s hack on “a security oversight by the mobile provider.”

Based on information compiled by KnowYourMeme, “Chuckling Squad” may have used a series of attacks on various minor celebrities two weeks ago as a dry run for the ones on Dorsey and Moretz. King Bach — at one point the most-followed individual on the now-defunct social media platform Vine — and popular YouTubers Keemstar and James Charles all blamed AT&T for the attacks, which occurred over Aug. 23-24, in tweets. The mobile provider did not respond to Page Six’s request for a comment on the hacks.

SIM card-based hacking — which involves contacting a mobile provider, pretending to be the target of the attack and asking the provider to transfer service to a new SIM card, which the hacker already owns — has been a prevalent threat in the tech world for at least two years now. In June 2018, a Vice article detailed the threat and spoke to several hackers who were familiar with the method. “With someone’s phone number,” one told the site, “you can get into every account they own within minutes and they can’t do anything about it.”

While the Vice article details a world where phone numbers and Instagram handles are bought and sold via online forums, it’s unclear if “Chuckling Squad” has any agenda beyond the novelty of temporarily forcing famous people to tweet memes and racial slurs. Wednesday afternoon, Twitter announced that it was suspending users’ ability to post to the platform via SMS.