I've got a former boss as a contact on LinkedIn. I don't trust them professionally, since I believe the company is unethical and he is part of the problem. I no longer work there, and there is virtually no chance that they will want to rehire me, as well.
I'm thinking of removing them as a contact. Does having them as a contact suggest that I approve of them on a professional level? If the answer is 'yes', then it seems like the responsible thing to do is to remove them; otherwise, there could be little downside (& upside).