You are underestimating Moderators here in Bitcointalk ?do you think they will just banned an account without truthful reason?
And why Moderator needs to Give them warning when they are literally making mistakes that can cause banning?
Sorry to say but majority of Bounty Hunters are cheaters and that is obvious reason why they are either Banned or red tagged.
and sometimes it is better to just banned them so the possibilities of making another mistakes will gone with their account.
and also don't act as your friends are really concerned about their low ranking accounts because they can create tons of it.
There's also a possibility that this he is just making up his "friends" to prevent the fact that he is ban evading. Bans are most likely due to spamming post or multi-accounts who got caught.
to OP. If by chance that this is actually true, then you should ask your friends about what they are seeing after they log in because the reason is probably stated. To be honest, I'd just wait for the ban to be lifted if it's only days and try to comply with the rules properly in the future.