Let's take another run at this. If there are no "buried" junction boxes, the owner should be able to find the junction box where this orphan wire is connected and disconnect it. Presto. Problem solved. There is no law against leaving unconnected scraps of wire inside a wall.

 

Its a very..very gray area as the NEC has very little to say about abandoned cabling unless its communication cables (which must be removed)

What?
I helped turn some kind of a communication center into a wooden leg shop and there were hundreds, maybe thousands of Ethernet cables left in the ceiling.

ps, it's not my problem. The shop went out of business and the next occupant is now in possession of hundreds or thousands of abandoned Ethernet cables.

 

There it is...
https://www.tlc-direct.co.uk/Products/AAJB20.html

 

What?
I helped turn some kind of a communication center into a wooden leg shop and there were hundreds, maybe thousands of Ethernet cables left in the ceiling.

ps, it's not my problem. The shop went out of business and the next occupant is now in possession of hundreds or thousands of abandoned Ethernet cables.

Its a "newer" addition to the NEC..

 

That sounds like a make-work program for electricians. Rip out wires so they can be replaced later.

 

It's also a make-money program. If I had enough time to rip those wires out, I could have sold them for their value in copper.