We have such blacklist, but it is currently manually curated (outside the code, and bot-specific ;-) ).
I am not too eager to allow a simple command from anyone to blacklist another user, it would need a little more than just that for it to be fair and effective.
But we do welcome you and every other tippingbot user to let us know who is abusing the system so we can blacklist them from tipping, or any use of the bot at all (less relevant now as it was in the past).

!ALIVE !INDEED !BBH

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