I think that might be illegal
Since the explosion of digital communication and the increase in businesses gaining and holding onto people’s details, there are more and more regulations popping up to ensure the safety and security of people’s data. This is a good thing, obviously, and stops nefarious companies selling on information or using it sneakily.
Mr. Solonsky has obviously decided that the rules don’t apply to him, as his customers are too important to him to just run away, leaving his company behind. In a lot of countries not having an unsubscribe button is actually illegal. Maybe he hoped no one would notice. Too bad that they did.