Probably, but they don't use a consistent approach. They do fight tooth and nail for that money.
I haven't paid for donkey's years and I've received a myriad of letters, had my account frozen twice, and the bailiff has come to my house four times since.
The last time the bailiff was in my home I refused to pay him (as I always do) and a couple of days later he sent me the usual letter announcing he was going to impound my bank account again. Curiously, that never happened; no idea why. This was about two years ago. I then got two or three more letters from them, the content of which I ignore, as I just sent them back as refused. I also got two letters from Creditreform (Inkasso?), which I also sent back unopened. Then silence for many months.
I recently got a roommate and that triggered the GEZ people into action again. He told them he's living with me and gave them my membership number. They then wrote to him that since I wasn't paying they were making him responsible for the dues at this address. They also wrote to me to tell me the same thing, and that they were "unsubscribing" me. "Wir haben Ihr Beitragskonto abgemeldet."