At my last company, when I joined they gave me an employee agreement to sign that not only granted to them the rights over any software that I developed while working for them even if it was personal projects that I did for myself on my own time (which is standard corporate bullshittery) but also granted to them rights over anything that I had developed in my entire life previous to working for them. I told them they had to be fucking kidding me (like, surely they should have understood that at a minimum that would conflict with the rights of my previous employers who I had developed stuff for) and refused to sign it. They ended up hiring me anyway, without my ever having signed any employee agreement at all - I got like weekly email reminders from HR about it for a year until they finally just stopped.