Place I used to work had a “we own all the IP you generate” clause, except it wasn’t very clearly written so could easily be read to mean literally all IP - write a song on the weekend, they own that. Got the wording tweaked in my contract to make it explicitly only cover things done in connection to my role, on company time, but I do wonder about my former colleagues. At least one of them has a mildly successful YouTube channel that I guess the company technically owns?