Not to add insult to injury, but these people posting on Reddit complaining about the money they have lost are opening themselves up to massive prison sentences. Reddit is a US site; all it takes to arrest everyone posting is to subpoena Reddit, get their IP's/emails/whatever, then raid their houses looking for drugs and whatever other contraband the police can find. Complaining publicly that you lost money on a site whose sole purpose was to sell illegal items is plenty of probable cause - especially with several implied death threats and people saying they may be killed over missing funds right in the thread. The feds will be all over this.
Not that they shouldn't complain somewhere, but maybe keep it on the darknet sites.