Did you even click the links? Almost every one is either dead, or points to an article about exchangers/payment processors getting shut down for being unlicensed exchangers/payment processors. I don't see anything about use of their money for illegal goods being the cause.
i'm reading them right now. opened first 9 links. all of them working.
exchangers raided, closed, jailed, 1 murder. one notice of being closed & out of business.
the illegal use is mostly gambling related or money laundering. what they have in common is internet.
bitcoin can be used for both.
gambling in the US is mostly illegal
and some exchangers were busted for being unlicensed or non AML compliant or any combination of those
some were busted for being linked to gambling. link to drugs is not the topic anymore, see ShadowOfHarbringer's comment