Thousands of Classic World of Warcraft accounts were temporarily banned across all servers on 12 November.
Here's what we know so far.
Latest News - Blizzard Unbans Accounts
Blizzard have officially reversed the ban decisions on all accounts banned in this erroneous wave.
In the email, Blizzard states: "After performing an additional review of the evidence considered in this action, we've determined that this closure was an error. We are reopening this license for play and hope you will accept our sincere apologies for the mistake."
Blue Post Speculated at Cause of Classic WoW Bans
According to a Blue Post from a Blizzard Customer Service agent, there was some speculation that these Classic WoW bans could be connected to a ground terrain exploit.

This, like other theories, is now confirmed as false.
Blizzard Seemed to Stand by Bans
According to Blizzard's customer support Twitter account, the company initially stood behind the bans as legitimate and not a mistake.

This was quickly remedied by Blizzard, who sent emails apologizing for the errors.
Classic WoW Ban Wave
Blizzard temporarily banned thousands of accounts in an erroneous ban wave in Classic WoW.

For each account holder, Blizzard have sent emails stating 14 day temporary bans for exploitation of game mechanics.
When players tried to log into their accounts, however, it displayed an 18,000+ day ban.
So what's happened?
Ban Details
It's hard to tell exactly happened for Blizzard's ban wave. The ban wave targeted accounts across multiple servers, but not all accounts.
In the end, Blizzard clarified the bans were an error, but no reason behind the error was given.
Speculation
Many players speculated on why these bans may have come.
Speculation ranged from purchasing gold to specific in-game actions like using Large Venom Sacs in AQ40. In the end, the issue was caused by an error on Blizzard's part. It has since been remedied.
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