How can someone get my auto insurance policy number to file a false claim on me?

I got a call from the claims department saying there's a claim that I hit a parked car. I didn't do it, I have no damages to my truck. I know the insurance will deny this person's claim against me, but what we can't figure out is how this person knows what insurance company I am with and how did they get my policy number? This person didn't file a claim with their insurance company until 1 day after filing a claim with mine. But I'm truly baffled on how they got my policy number!!! Any ideas on how some random person can get obtain your policy number? Please advise as I feel this is a breach of my privacy. Thanks!