You agree to undergo AML/KYC procedures at any time Exolix requests. This can include providing valid state documents and information on fund origin.
Most people cannot even provide such a source of funds beyond a transaction hash, username and website because it's largely peer to peer.
<I think asking for unrelated documents such as salary invoice is diabolical because there's no way to prove that the user actually sent coins from that source.>
Awareness about the source of income is a greater invasion of privacy than a simple Know Your Customer (KYC) request. Even my wife does not know all my sources of income; she never even asked for them. In the end, it can sometimes be quite difficult to explain them to anyone.
I know about Exolix from the Orangefren website. I won't go into their deal, but using Exolix through Orangefren has much more flexible conditions (or so they claim). This leads me to the conclusion that Exolix KYC requirements are just a whim, because there are conditions when KYC is not necessary.