Just had this from noip.com:
Free Dynamic DNS hosts must be confirmed every 30 days by logging into your No-IP account and clicking update.
If you are still using blahblahblah and do not wish to have it removed from our system, please click the link below to confirm your hostname:
Didn't see any mention of that when signing up.... (might have not looked very carefully I suppose).... And when you click the confirmation link there is one of those infuriating recaptcha things to input.
Now looking for another provider....
https://freedns.afraid.org/ if that bothers you