Mojang's putting its blocky foot down when it comes to brands and Minecraft. In an open letter to the community on its site, Owen Hill, the company's director of creative communications, laid out new guidelines specifically directed at companies, ad agencies and any other non-gamer entities looking to capitalize on Minecraft's massive user community. For an idea of just how vast that base is, consider that, in 2014, creator Markus "Notch" Persson revealed that the PC version had over 100 million registered users. It's understandable that a pool of users that large would prove a tempting lure for brands that want to market their wholly unrelated wares to the community. But no more -- according to the new building promotion guidelines, it's no longer permissible to build servers or maps to "promote unrelated products in playable form."