Lately, WoW community players have been asking if Blizzard can ban you for playing on a private server. Concerning this subject, there have been several contrary opinions. Some say you cannot, others say you can. You do not even know which to believe.
To know the solid details on this matter, here’s what our industry experts have to say:
Can You Get Banned for Using Private Servers for Blizzard Games?
It would be best if you do not use a private server for Blizzard games because they are free and readily available. The implication thereof can be devastating. You can lose your account for life if they ban you.
Blizzard's Private Server Policy
Since you agree to these terms before using their product and services, you are answerable for any illegality  arising from the usage of the product.
Blizzard Suing Private Server Operators
Recently they sued Scapegaming for copyright infringement. They won the case, and the court awarded $88 million. Although Scapegaming has not responded to the lawsuit, this gives us a clear picture of how Blizzard plans to deal with private server operators.
Can I play on a WoW private server?
We do not advise you to play on a WoW private server. You are bound to only play on the Blizzard server and not a third-party private server.
As explained above, Blizzard can indeed ban you from playing on a private server for their games. Also, keep in mind that Blizzard reserves the right to file lawsuits against individuals or organizations who violate their terms of service and use.