My response to you would be the following:
1. Working for a company doesn't mean you agree with everything they do.
2. Just because some of the work you do is used by someone else for something you don't agree with doesn't mean that you're evil by default.
3. Try to find a tool that can't be used for "evil". Seriously, I doubt you can find a single thing, whether a device or an application that can't both do good and bad. Should your friends refuse to create anything because it might be put to a use they don't agree with?
4. How do you know they haven't stopped things that you would have considered even worse? Pretty much any job is going to have stuff that you can't talk about, whether for IP, legal, or other reasons.
And at the end of the day, your friends have their own moral codes, just like you do. If they feel that the work they do fits their code, then that's their decision.