Both of those articles were in relation to a single instance (the second article actually commenting on the first) of Paypal requiring a buyer to destroy the supposed counterfeit item (a violin). They do not address whether the violin actually
was counterfeit or not, but refer back to a From Paypal's T&C:
"If an international buyer purchases an item, the buyer will be instructed to provide PayPal with evidence (documentation from a 3rd party) that the item is counterfeit. PayPal will validate the documentation and then ask the buyer to destroy the item and attest to this action by signing an affidavit."
The original blog post that they are referring to is here:
http://www.regretsy.com/2012/01/03/from-the-mailbag-27/
I'll preface the rest of this by saying I know zilch about violins: My guess is that the seller's description was misleading (whether intentionally or not) as to the origin/authenticity of the violin, and their statement of "They somehow deemed the violin as “counterfeit” even though there is no such thing in the violin world” seems to point to that as well. I have encountered very few items valued in the thousands of dollars that someone somewhere hasn't tried to fake. I think the "labelling issues" that the blogger/seller refers to are what most others would call "authenticity issues."
Regardless, even if the seller was 100% in the right and truly taken advantage of by the situation, I really don't think this is a rampant issue or that one blog post and two articles referring to that blog post are evidence of an epidemic. Paypal and eBay alike have plenty of other loopholes that allow crooked buyers to take advantage of sellers (and vice versa) to get bent out of shape over this one instance. I for one won't be closing down my eBay selling over this report any more than I would shut down a brick and mortar store because I found out someone had been shoplifting.