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Spammers prefer memospam because it's private. Once they spam in comments, the community and accounts like @steemcleaners and @spaminator will burn their reputation below zero.

It's easy to downvote them into invisibility that way.
Which is why they don't do it now.

True, plus it hurts their reputation 😀

@Drako i think this is a way more reasonable to all including new and small fish like me.
People can mark them as spammers and they can lose their reputaion