It doesn't mean if you used those coins you have something shady to hide. Maybe you just like to keep more private in hiding your money/invested that's why you prefer to used those "privacy coins". But I'm sure that small percentage of criminals are really using crypto, to masked and hid their wealth. As for regulations? well most countries has already put a tighter grip, KYC is already required so I don't know what more can they ask for us. And I think authorities are really upgrading their system as well, (https://www.ccn.com/busted-britain-confiscates-700000-in-bitcoin-from-hacker/). So it looks like they are gaining some grounds on this criminals or hackers taking advantage of crypto's pseudo-anonymous or privacy feature.