[Shin Noir]

Note everything below is just my opinion.

Legend:
IP = intellectual property, this is the creative either patented, copyrighted, or protected in other ways by a company.
DBG: Daybreak Games, the current owner of the Everquest franchise.
P99: Project 1999, a private eqemu server.

That aside, P99 shows that DBG is at least amiable to the approach of emulated servers. Once a server gets significant enough to catch the attention of DBG, either positively or negatively, is the only time you'll truly know how compliant you are to DBG's terms. Notice in P99's case, DBG was looking for compliance, namely the upcoming progression servers, they felt the release of velious in P99 clashed competitively with the progression server's opportunity to attract players. It was discussed (those terms were not heavily disclosed), and as long as P99 retains compliance (in this case, they delayed Velious release) it shows some reassurance that DBG is not extremely evil about entirely shutting off private servers at this time. (Some gaming companies are aggressive about this)

If a server is not making significant money or equal value in other means (high traffic/population/attention), there's a decent chance you'll stay under the radar until a sweep occurs (where DBG lawyers sweep across offenders of a certain criteria generically sending letters of violation) and that sweep will likely be a cease and desist, with terms in order to restore a compliant nature. I don't think I've ever heard of a sweep happening on Everquest however.

Some times a sweep will have a request a takedown notice of the server when DBG's lawyers feels it's a bad enough offense that hurts the business or protection of IP, but it's case by case, and I don't think there's any way currently to officially know a server's standings are in DBG's view until such terms are discussed between entities. There are laws that should be abided to regardless. General rule, if you're making money off someone else's IP, there are a lot of laws to protect the IP holder, the question ultimately becomes if it is in the interest of DBG to prosecute or not. (And if it's worth the money or recovery of cumulative damages, since lawyers aren't cheap as well as lost revenue is not ideal to any company)