Or bought with a stolen credit/debit card.
In that case it is even worse.It's really a 'big problem' 
That depends. Do you want to make this forum a nest for hackers and associate Bitcoin with them? If so, then there is no problem at all. I might have incorrectly expressed myself here (it's still too early for me). If there are indications that the goods are stolen/hacked then I will remove them until there's some official clarification (around here). I have only deleted a very small number of them (most were duplicates by the same seller though).