Just saw a great point by BBMC about multisig.
When coin normally passes through a market it is mixed and tumbled a bit. It's still dirty coins but just like a bitcoin wallet you don't know exactly who it belongs to.
With multisig LE can make a buy and immediately identify a particular vendors wallet.
Is helix for instance really sufficient to thwart any attempt at blockchain analysis?
What if any extra steps should be taken on buyer or vendor side?
I would imagine the high volume vendors to be most at risk but I'm unsure that this really differs from doing direct deals at all except some vendors might use a helix address to receive payment from buyers.
I've never done a direct deal with any vendor so I dunno what the whole process is.
Will someone educate me?
/u/VendorBBMC and anyone else that's worried about multisig is retarded or completely incompetent with bitcoin. There is no way to tie other addresses in a wallet to each other unless you have the MPK (master public key). As long as you don't give that away, LE has only a single address. The same that they do if you make a withdrawl from the site and they seize the server. No different, no more stress. Just idiots that don't understand stuff. Thus we will never get nice things.