Hurdles for those who want to protect trademarks for cannabis related goods and services.

"Most cannabis-related activities cannot be lawfully regulated by Congress, and the USPTO has taken the position that trademarks used in connection with these activities cannot be registered. However, it is possible to secure trademark rights for ancillary goods or services which, while related to cannabis, are not technically illegal."

http://www.natlawreview.com/article/cannabis-conundrum-hurdles-to-trademark-protection-growing-industry