. Unfortunately Blizzard / EA has nothing to do with this as far as I know. "private" servers, as in free shards for UO = hacked servers run by random people so people can play for free instead of paying the monthly fee and play on the actual "real"/"public" servers.
Quote from the wiki:
RunUO is not an Approved Third Party Program, and using it with the Ultima Online Client is a violation of the clientís End User License Agreement (EULA) If Electronic Arts suspects that a user has used RunUO or connected to a RunUO freeshard in the past,EA may revoke that userís EA account. This does not hamper their ability to connect to non EA shards however. (RunUO or otherwise) Shard Emulation is not illegal, contrary to many rumors and misconceptions, as no reverse engineering takes place.
UO Free shards used to be huge at one point, now the "free WOW" servers are the next "big" thing. I don't think any "industry professional" would have any interest or need to work with these kind of projects. And the wiki quote is a bit misleading, the only way to pretty much join the free shards was to go around it a bit and force it to connect into a different server instead of the UO's own server.
And thus all free shard players were pretty much breaking the EULA and none of them cared because they were playing on the free servers and not on the "pay as you go" UO servers. No account to ban so nothing to loose.