Although, as an active member of the community, it's nearly impossible to have missed this huge issue, I think it's very important to warn people for this.
What happened is a large case fraud in which apparently one user (under multiple names) scammed several members of DeviantArt community. Leaving some people as much as $3000 in debt!!! Money they, most likely, never see back.
Even though the user is banned by DeviantArt now, there's no reason why it won't happen again.
After all, the problem is caused by a loophole in PayPal's rules. So basically everybody that's using PayPal for its business (and that's a lot of us) is at risk.
People doing commissions
People selling adoptables
To understand where all of this comes from, it's first of all important to know what a PayPal chargeback actually is.
This video offers a proper explanation of what chargeback is, and what it should be used for.
Seeing how the video talks about 'proof of shipment' or 'proof of contract', it's easy to understand how easy it is to scam people with this. And why this way of scamming makes so many victims on websites like DeviantArt. After all; many of us sell digital goods (no shipment) and work without a contract (since it's often a one-time customer). There are, however, a number of ways to protect yourself against this kind of fraud, as are listed in the journal below.
And a few years of freelancing experience helped me come up with these golden rules:
Check your customer. How long does he have an account? Are there other artists having experience with this customer?
Google your customer's name. If he appears on fraud sites, it's not a good sign (Yes, people. Sometimes it's as easy as this).
People coming up with fishy reasons to delay payments is often a no-go.
If something seems too good to be true, it often is.
Trust your feelings. If something doesn't feel right, then don't do it.
And be careful!