What they are doing is direct violation of GDPR and a really bad idea. There was a complaint filled this morning agains Google, Facebook, Whatsapp and Instagram doing something similar but to lesser extent.
I just cant understand why is everyone trying to push all its intelectual power into trying to workaround GDPR instead of trying to comply, for most website it is trivial as they are in breach of GDPR just becoase they collect the data they dont need.