But casinos (for example) have a tacit agreement with the "criminal industry" in general, that criminals will be able to inherently launder money through the cash-in/cash-out mechanisms of the casino, in exchange for having to play some table games (and therefore lose at least a small percentage of their money, i.e. give a percentage of their ill-gotten gains to the casino) to make everything look legitimate.
If a given business has a business model where it would not possibly stay afloat over the long term, if not for some appreciable fraction of its customer base making use of the business for money laundering — then the business is a "knowing participant" to the general concept of money laundering, even if they have never shaken hands with any specific criminals. Their MBAs knowingly design the business around enabling money laundering.
Come to think of it, this is a bit like the argument the US DOJ used to take down Napster — which actually, finally somewhat convinces me of the logic they used.
The Napster company's business model depended upon some appreciable fraction of its clientele being IP pirates. For everyone else, Napster was a vitamin; but for pirates, Napster was a painkiller. Napster would never have achieved spread without a core base of pirates to spread it. The Napster company's business model (presumably something like "make the software widely used, then sell ads that display in the client" or something) depended on — was planned around — piracy. Thus, Napster was in tacit collusion with pirates; just as most money launderers are in tacit collusion with gangsters.