I would assume with a heavy amount of money like $500 going into coinbase, or multiple purchases adding up in money, a bank would like to at least see where the money is going towards. Considering it's never coming back out, I see how it could be a problem. Is it actually something to worry about though if there is no current investigation for a darknet user?
$500 is a heavy amount of money? Looks like I'm fucked good and proper then lol.