Calling the police is largely a waste of time unless you live in one of the few areas where the police might actually do something about it. That said, I've had enough "close calls" over the years not to worry about them all that much. I've actually had incidents where passing cars have actually hit me and I've continued riding along with no more than a twitch.
If you're really that worried about it, your only option is to ride a little further from the kerb so you have a little more space in which to back off if they come too close. If you really want to "get them back" after the event, just blow them a kiss. That said, I'm more into just riding on these days and forgetting about it. Yes, they passed too close, but once they're gone, they're gone. If you let it get to you, all you'll do is ruin the rest of your ride.
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I am clinically insane. I am proud of it.
That is all.