I should hope there's more to that case than meets the eye. There should be reasonable belief that an offence has been committed for a warrant. I don't think receiving a large sum from an exchange would be sufficient for money laundering charges without some kind of incriminating evidence (IANAL of course).
I had that exact thing happen to me due to depositing 30k euro over the course of a year, transferring it to a bitcoin exchange.
You guys sure are good at making bitcoin look like a giant scam by claiming the purpose is to "be your own bank" and then dumping all the bitcoins for fiat and putting the fiat into a bank. You even failed the idiot test of converting shitcoins into green tinted, Jewish confetti instead of physical metals.