Well every two weeks or so I get unsolicited mails offering to sell me very large databases of contact information. My standard is to just completely ignore th

Well every two weeks or so I get unsolicited mails offering to sell me very large databases of contact information. My standard is to just completely ignore these, but when I got nagged for the third time recently I sent them a (very intrusive but still legally entirely legitimate) subject access request to find out what they have on me, who they got it from and who they have sold it to as it was entirely without consent.