As a customer on HANSA market, I got ripped off my money multiple times this way. I'll explain with 2 examples.
Example 1 I ordered a powder from a vendor (won't go into detail here) on HANSA market. Shipping was very fast and stealth was good. Upon testing the powder, the powder was inactive. I sent a dispute to this vendor, as usual claming he has quality powders and only has positive feedback. Dispute couldn't be solved between the vendor and I, so I contacted someone from HANSA. Their answer? "We can't give a refund for this, check our refund policy: it says 'no refund for powders of insufficient quality'. The vendor has no negative feedback, so we have released funds from escrow to the vendor". So a vendor can send me flour and win a dispute - wtf? Of course he can't do this for all his orders, but it's a sustainable manner to maintain positive reviews and still be a selective scammer.
Example 2 I ordered blotters from a vendor, received everything in time. Tried the stuff, the thing worked similar to the chemical on the blotter but was an RC. I got a horrible tongue reaction from this. My tongue was burnt chemically which allowed oral thrush to develop. It was only 3 hours after I had taken this chemical that I looked in the mirror because my tongue hurt. I saw some white skins coming loose and was texting a friend about this, but he said I was tripping. One night of sleep and it looked like this - only click if you really want to see it - it was horrible. I finalized the order and wrote a review (had to open a dispute, but was new to Hansa then and didn't know how it worked 100% yet). The review got deleted eventually and I didn't have my money back.
Luckily I only ordered small amounts.
Just warning here you here, I won't name any vendors.
UPDATE: Because everyone wants to know the names. I ordered alprazolam from JunoTempleh and LSD from DougHeffernan
Why? Name and shame the fuck out of them if they're really in the wrong.