Banks and most sites requiring age verification are _littered_ with tracking software that does _literally_ this. Further, if you put on an adblocker and I get

Banks and most sites requiring age verification are _littered_ with tracking software that does _literally_ this. Further, if you put on an adblocker and I get access to the logs at ironbank and hornpub; I could just query them for your IP address. Collusion to this degree is possible, but doesn't seem worth worrying about if the aforementioned attack vectors still exist. My $0.02.