Assuming you don't attempt to tell them to do something I'm not actually sure you would. The first amendment is pretty strong, but ianal.
> Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
This seems to be orthogonal to the issue of influencing someone to do something and being held partially responsible for the outcome.
Yes, that's what it seems like. They deliberately engineered 4o to agree with virtually anything the user said, ostensibly to boost engagement numbers. This was at the very least negligently reckless.