Facebook has shut down pages offering marijuana for sale in Alaska, angering the businesses that run them, who say they were licensed to sell it.
It highlights the problems faced by social networks trying to set boundaries for what users can post.
The National Cannabis Industry Association said it was seeking “clearer guidelines” from Facebook.
Affected businesses should appeal to have their accounts restored, the NCIA told the Associated Press news agency.
The issue had affected all of the nine US states that had legalised recreational and medical cannabis, deputy director Taylor West added.
Facebook was not able to provide immediate comment on the matter.
TV and radio advertising about legal marijuana is often restricted, meaning social media can be a vital way to communicate with customers.
Leah Levington, who owns cannabis business Enlighten Alaska, told AP the take-down was “frustrating” and she was worried her Instagram account could also be shut down.