Worrying about free software advocates using the law against others is hilarious. It's like worrying about Walmart cashiers demanding to make more money than software developers.
It's not and I am glad it isn't. The GPL is sometimes enforced and rightly so, code authors choose this license and donated their time and skill under this condition (the GPL) of their choosing. Re-licensing it or ignoring the licenses is a crime, you lied that you would uphold the license when you started using the software.
Don't get me wrong, I love the GPL, I love free software! Choosing a license though, GPL or proprietary, is entirely up to the author of a piece of code though. Forcing open licenses upon authors is detrimental to freedom in general.
Worrying or not worrying about it has nothing to do with the ethics of breaking the GPL (or any license).
I see someone hasn't had GPL conflicts in their code base before. There is a reason companies specifically look for them and it's because the FSF and it's communities will make your life hell.
Try using proprietary libraries in your software without complying with their licenses and you'll see what having your life made hell means. GPL license holders barely ever sued anyone, and when they do (like FSF v Cisco), it's usually after years of trying to get them to comply. That they (rightly) complain about your practices is not using the law.
Don't get me wrong, I love the GPL, I love free software! Choosing a license though, GPL or proprietary, is entirely up to the author of a piece of code though. Forcing open licenses upon authors is detrimental to freedom in general.
Worrying or not worrying about it has nothing to do with the ethics of breaking the GPL (or any license).