What just happened? It's not just Instagram that's under scrutiny for its impact on young users. TikTok is being investigated by a nationwide group of state attorneys general over the potential harm it causes to younger people's mental and physical health.

Attorneys general from eight states, including Massachusetts, California, Florida, and Kentucky, are investigating TikTok to find out if its design and the way it is promoted can have a negative effect on the wellbeing of children, teens, and young adults.

"As children and teens already grapple with issues of anxiety, social pressure and depression, we cannot allow social media to further harm their physical health and mental well-being," Maura Healey, the attorney general of Massachusetts, said in a statement. "State attorneys general have an imperative to protect young people and seek more information about how companies like TikTok are influencing their daily lives."

Healy added that the investigation will focus on "the methods and techniques" TikTok uses to "boost young user engagement, including increasing the duration of time spent on the platform."

Connecticut Attorney General William Tong cited "reckless viral challenges" on TikTok as a huge concern. Some of the more dangerous trends originating from the site include stacking milk crates into stairs and climbing them, cracking people's backs, dry scooping pre-workout powders (it lead to a 22-year old suffering a heart attack), and "scalp popping," which involves pulling sharply on a lock of hair to create a "pop" sound.

"Our investigation will look at what TikTok knew about the risks to our children, and precisely what they have been doing to keep our kids online," Tong said.

The investigation comes after a whistleblower last year revealed Facebook knew exactly how damaging Instagram is to teenage girls' mental health but ignored its own internal research. Facebook denied this was the case, but it still put the brakes on the Instagram for Kids project.

The issue even made it into the state of the Union address, with President Biden urging more regulatory protections for young people online. "We must hold social media accountable for the national experiment they're conducting on our children for profit," he said.

In other TikTok news, many users are less than pleased about it increasing the maximum length of uploaded videos to ten minutes, claiming the platform is losing its defining feature and becoming more like YouTube.