I've gotten them from recruitment agencies I thought I had unsubscribed from and gotten rid of for good. Nope.
There is a simple rule of thumb you should know.
ANYTHING THAT EVER GETS WRITTEN ON A HARDDISK ON A COMPUTER SOMEWHERE, WILL STAY THERE UNTIL THE END OF TIMES !
Harddisks are getting too cheap nowadays. We're thinking in Gigabytes or Terrabytes now. Because movies are easily a few GBs on a HDD. But in general, data is getting very tiny, compared to the size of disks. Suppose you need a 10,000 bytes (10KB) to store basic data about any person. Name, address, age, bank info, security number. Hobbies. People you know. History of what you did. Which schools you attended. Lots of stuff. As long as it isn't sound, picture or film. You can store much more than you think. For 10KB for 7 billion people, you only need 70 TeraByte of data. That's a few disks in a single computer. A desktop computer even. Do you realize what that means ? ALL BASIC DATA about EVERY LIVING PERSON can be stored in a single computer.
When storage is so cheap, nothing will ever get deleted. Companies might tell you they will delete your data. But they won't. Get used to it.