The only thing that seems off in that thread is accusing them of being a thief. They could be someone who found / stole an iPod, but legitimate auctions do happen when unclaimed goods are redistributed.
You could be right, but what if you're wrong and very publicly accusing someone of being a criminal?
In the end, if you ask a thief if they are, they will say no and if you ask a non-thief if they are a thief, they too will say no, but also potentially be upset / offended / have a legitimate complaint about calling their morals into question.
If something is totally, clearly illegal - we often delete / edit it - but when there is room for a legitimate case, we tend to be open to the assumption that people are good and the post is offered in good faith.