I wonder if this is why they axed all of their "firearms sales"

https://www.engadget.com/2018/03/21/reddit-bans-communities-...

     The social site has updated its policies to ban
     the trade of firearms, explosives, drugs (including
     alcohol and tobacco), services with "physical sexual 
     contact," stolen goods, personal info and 
     counterfeits. Accordingly, Reddit has shut down 
     numerous subreddits that either directly traded 
     in these goods or were clearly meant to enable those 
     exchanges, including r/gunsforsale, r/stealing (yes, 
     it existed) and r/darknetmarkets.

Perhaps they were taking a broad interpretation of something in the legal language.