What are dirty coins?
If anybody who has Bitcoins makes a crime (for example the owner of laser.online that stolen Bitcoins). these Bitcoins are dirty.
So such a person tries to get rid of them. For example he tries to change them into Fiat or buys Altcoins. If I am the person who gives this person my Altcoins and this person pays me with the dirty Bitcoins I have now this Bitcoins. No I have dirty Bitcoins. (Bitcoins with a dirty source Bitcoin Address)

Qurstion
1) Are there exchanges who have a black list of such dirty Bitcoins. A
2) And if a user who has such Bitcoins transfers them to such an exchange will become suspicious.

3) could there be a system tocheck, how clean my Bitcoins are?

I am thinking aloud after being scamed by laser

I have started seeming lending coin moving to wave platform maybe when they saw what bitcoin is doing to their potential clients... Delay of payment, high transaction fee...etc.....I think we will start to see more shift on waves....can u identify some lending coins on waves?