I have a very early Gmail account I still use which collects an unbelievable amount of other people's emails who cannot be bothered to fill out a form correctly, hotel reservations, insurances. I could cancel them all easily and mess with people but I delete and move on.
It's easy to be a bad actor given the conditions that the internet was built on.
There was a CCC talk with a similar approach, where researches bought expired government domains and typo / bit flip domains. For example: bund.de is managed by the German Federal Government and they purchased bund.ee, the Estonian TLD, which is both a typo and bit flip and started watching email and DNS requests coming in.