I hadn't though about it this way until now, but having the ability to achieve full anonymity on the internet enables things like this, and assassination markets might not be the first or most viscous thing enabled by anonymity.

I can imagine that if assassination markets were to take off, you'd see some large bounties (in excess of $100k) on every major politician in the world. Pretty much any figure of high popularity would probably have some sort of assassination bounty on their head, because the more popular you are, the more haters you have.

What other sorts of unacceptable things could you do given fully anonymous money coupled with a fully anonymous internet identity? I can think of:

website takedowns

funding murder, rape, arson, etc.

bombing certain buildings

funding smear campaigns (say, tear the clothes off a popular celebrity or something)

bounties for drugs, child porn, etc.

kidnappings

doxing

You could basically attempt to crowd fund any illegal activity.