I see a lot of people selling adobe contributor accounts on facebook

There's no such thing as Adobe Contributor Accounts. 

The closest thing I can think of is a Stock Contributor Account-holder is trying to find a private party buyer for their Stock Image/Video Collection.  Stock is a global royalty-free assets service. But that would require a legal transfer of ownership drawn up by an attorney experienced in digital property and copyright laws.

If you see something offered on Facebook or FB Marketplace, take it with a very healthy dose of skepticism. Ask lots of questions about what they're actually selling. Genuine sellers of digital artwork don't usually look for buyers on Facebook. 

not unless they have written permission from adobe (whcih is unlikely).

As of March 25, 2025, contributors are not permitted to create and operate multiple contributor accounts unless you have written approval from Adobe Stock. Exceptions may be considered for certain contributor businesses based on specific operational needs.