It is not prohibited at all. Steemit is intended to be censorship free and open for any discussion.
Steemcleaners is NOT an official Steemit account, but simply a user-made account like any other. Under the guise of anti-spam many innocent and honest Steemians are being demonetized over personal bias versus certain projects, amongst other issues. I am raising these problems with Steemcleaners in a thread I made yesterday. Please consider visiting it and possibly throwing in your support against this over-moderation: https://steemit.com/steemit/@pandorasbox/steemcleaners-abuse-or-malfunction-honest-people-are-getting-flagged-unfairly-censorship-under-the-guise-of-anti-spam-are-you#@idealsceneprod/re-steemcleaners-re-pandorasbox-steemcleaners-abuse-or-malfunction-honest-people-are-getting-flagged-unfairly-censorship-under-the-guise-of-anti-spam-are-you-20170908t183305865z