It was pretty obvious, even if you only looked at the volume they reported on their front page; for example, I'll quote what I wrote elsewhere in august:
bitexbay's volume numbers are obviously fabricated, at the moment they show 51,882 btc volume on the month, 12,105 btc on the week -- (7/30)*51882==12105.8 -- not to mention that in the past 8 days, their 30 day volume has supposedly gone from around 14k btc to 51k btc.
There were a couple other times I checked as well (I could dig them up if anyone wants), and the ratio matched perfectly each time .. not to mention that there is no way on earth they would have such volume.