[4ntonius8lock]

This works. And I do it. Too many unhinged people out there. Here in the US, I've found things in restaurants a couple of times and pointed it to the staff.

It clears the liability for all involved, since no one can claim that the staff or a fellow patron 'took it'. It was pointed out by a customer and removed with witnesses. I generally mention it to more than one staff.

I try to baseline assume that the person I'm dealing with in public is not fully there (which would include the property owner). It makes it easier to deal with when it is actually the case.