I recently posted an ad. Immediately I was contacted by a Kleinanzeiger user, saying that she wanted to buy the object, and would pay the postage: could I just let her know the total price. She sent me her address and asked for my PayPal ID to make the money transfer. I disguised my PayPal ID (email address, because PayPal doesn't allow a different type of ID) to make it machine-unreadable. That was the end of the "conversation" with the other user who -- I checked -- had been with Kleinanzeigen for a few years, and has a rating of "not great". Then, I opened the Emails on my computer, and had a rush of spam mails. These continued -- increasingly new ones -- for days and weeks. Despite trying to "desubscribe" from all of these spurious "services", I am still getting 10s of spam mails each day. I am convince that there was a connection to the event on Kleinanzeigen: it's quite obvious: my encoded email address was probably read by a real person -- quite possibly the very person acting as the very enthusiastic buyer of my advertised object. If my theory is true, that person is actually acting as an "email harvester", and earning money. And all this happens on Kleinanzeigen, which seems not to care much about it. I submitted my case, giving all details, and was then told by Kleinanzeigen that it wasn't going to pursue it further. 2 years ago I was defrauded out of more than 3,000 Euros via fake seller on Kleinanzeigen who seemed to have hacked into a genuine seller's account. All in all this platform has descended into junk that is full of fraud and advertising. Use it at your peril.