I maintain email systems for a living and it's a completely legitimate hack. Capital 'S' spammers don't care because they hit wide swaths of email addresses by

I maintain email systems for a living and it's a completely legitimate hack. Capital 'S' spammers don't care because they hit wide swaths of email addresses by generating random strings. They don't waste money buying data. On the other hand, when someone is buying your data from Equifax, there might be some real bright actors out there, but the majority of firms engaging in this kind of behavior are not as technologically robust as you would think. So you will still catch people sharing your email address regularly. Besides, if you have + modifiers in your email, they don't know what sort of shenanigans you might actually be doing with it. For all they know, it's a DLL with a re-router or it junks all non-modified emails.