As someone who was in an industry that I later discovered was doing things I wasn't personally ethically okay with, I would advise them to do similar to me. Start looking for a new gig and just get out as soon as you can.
Unfortunately as an individual there just isn't much you can do. There will always be someone willing to do the job that you aren't willing to do. Just get out and find something you can sleep at night doing
I'd also recommend you actually find out about somebody's background before making such a giant assumption about how much they know about the issue.
And if you don't think DRM has been used to abuse legitimate users, you yourself have a significant amount of understanding the other side to do. A great start might be just reviewing some of the anecdotes in this comment section or any of the other many threads that continually happen on HN. It turns out that DRM technology has actually changed a bit in the last 24 years, and it's not just about "protecting" IP
I started on another side of engineering and I get that. Building rockets is exciting and fun. But while you build those things it's easy to forget you're building something much more destructive.