> are to be no off-topic conversations during work of any kind, and it would have to have been demonstrably enforced
This is silly.
Go read your contract. It most likely has something exactly like this in it, in addition to spelling out what you are allowed to use company property and time for. This is employer 101 level stuff folks.
> demonstrably enforced
Telling someone to get back to work once in a while is enforcement.
You can continue contorting this into some sort of pro-union/organization thing - but it is not.
These people literally:
1) Started their work day
2) Used their company-provided computer to browse the internet instead of working
3) Used their company-provided email address to sign up for a non-work-related website
4) If successful in creating the account, would proceed to spend company time gossiping about company policies.
On it's own that's a terminatable offense and a gross misuse of company time, money and property.