I discovers this 10 years ago with Yelp. I refused to pay, but still kept an account linked to Faceboook. When I deleted that account, apparently Yelp knew that and released some old negative reviews that previously had been hidden. One review was filled with lies, and I never had the chance to see it (much less respond to it) when I still had the account. That was the day that I learned what legal online extortion looks like.

City-level reddit subs have a fair idea where to avoid, I find.