This is a good question, and perhaps the best thing to do is to have a clear policy in place on whats OK and whats not. Beyond that, of course its completely up

This is a good question, and perhaps the best thing to do is to have a clear policy in place on whats OK and whats not. Beyond that, of course its completely upto the person. You can never know how someone will behave in every circumstance, so you can only do so much.