If you were right, it wouldn't be so egregious. Unfortunately, due to lower hiring standards, expedited processes, and a general nonchalance towards the law, plenty of legal immigrants, green card holders, and even natural-born citizens have been wrongfully arrested by ICE because they fit the profile of who they're looking for. Just look up "ICE deports legal immigrant", and you'll find dozens and dozens of stories about various cases involving it.

And regardless of if it's intentional, if it's negligence, if it's just an acceptable margin of error, either way, if you're a legal immigrant, you very much do still have to worry about ICE.