Thread has 30 pages and reading every thread I realized that many people used service provided by him, why the hell did not people pay higher fees to avoid being deceived by this guy? I'm also having trouble noticing something, you said:
I saw this guy's tx acceleration service, and paid 0.00071741 to him.
He went vanish right after I send him the payment.
You paid the guy to speed up your transaction, right, and the guy disappears, the guy no longer responds to you, but that alone is not enough to accuse him of being a scammer, you know if he really accelerated your transaction or you have prove that he did not speed up his transaction? if you can prove that he has not accelerated your transaction after receiving your bitcoin, then you have reasons to accuse him of being a scammer because if he did not speed up his transaction he broke the agreement that the two of you signed.
Then he went vanish right after I paid him, and my tx is still not confirmed. Isn't this clear enough?