I am a not so old member on this site but from my experience (i don't know if you belive me but seriously i have a lot) i must say Middle Man service is not secured by far.Why?! Well one of the reason is that peoples don't follow rules posted on website by our superiors.
Finally my advice is to check twice before start a trade.
Check out these links also posted by Lowfyr :
1)

2)

1 more usefull advice also: BE SURE WHO YOU ARE TALKING TO!!!
Are a lot of scammers who pretend are a famous MiddleMan but are only fakes.Ask him to send you a PM on EPVP to be sure.Check out this link posted by Kuh also :

I HOPE THESE INFOS WILL PREVENT SOME SCAMMERS TO DO THEIR JOB!






