Comment by D-Machine

Yup, agreed. I don't trust these companies for a second, but I also don't want overreach.

Also, though this isn't super relevant, I am not actually personally too worried if they are really using behavioural psychologists. Most psychology is such junk science and most research psychologists struggle with such basic math and stats that I am extremely skeptical they'd be gaining anything from having a person like that on hand.

I think the reality is that the addictiveness is engineered with simple A/B and other kinds of testing and data, and this kind of engineering / research is better done by people with other qualifications. This would be the thing to look for and demand documentation and evidence about, if we were serious about limiting this kind of thing.