The new usage guidelines for the game set out how consumers of Minecraft (players, server owners, content creators, and the like) are allowed to use the game and how they may use the "Minecraft" brand name in their work.
One of the primary issues causing controversy is the general wording featured in a clause that states that any content may be taken down
at any time if we [Mojang] think that it is appropriate to do so, or we [Mojang] don't like what you are doing.
This is interpreted to mean that any content can be taken down at any time, for no reason.
Another controversial change is a clause stating that servers may no longer limit access to only players that own specific out-of-game content.
It further states that if the server is to have paid access, all players must be able to purchase this access and the cost must be the same for all players.
This is interpreted by players to likely affect the popular anarchy server 2b2t, which has a player queue when joining. Players are able to purchase priority tickets for this queue.
All servers must also now be suitable for children, with
gambling, pornography, violence, terrorism, explicit lyrics, or other unsafe/mature content
no longer being allowed.
The commercial usage guidelines are also changed to now encompass
any non-commercial blogs, servers, community forums, fan sites, fan clubs, news groups, events, and gatherings.
Any in-person events related to the game are not allowed to
use official Minecraft brand or assets on marketing materials create[d]
and may not accept for-profit sponserships. The "Minecraft" name may be used now
in a secondary name, secondary title, or description only.
Other changes include all servers being obligated to include "not associated with Mojang" disclaimers as well as terms of service disclaimers.
The full usage guidelines can be viewed on the Minecraft website.