Here's my take on it:
1. Email/call them and just find out what's going on. "I understand that your plans may have changed, but an update from you on the status of this transaction would at least be professional and courteous."
2. I followed up on an overdue payment on a deal agreed to by email a few months ago and the guy said he was in the hospital and that he'd get back to me. Its been another month and I've still heard nothing. I could continue to nag him, but what if I found out the guy had cancer or something? There are more important things than domains or business.
3. If you're absolutely sure they're ghosting you, the next question is, are they a domainer? Or an end user? Since I doubt you're selling anything good cheap, I'm guessing you're not selling to a domainer, but more likely an end user.
a) Calling out a likely end-user is just a waste of your time and effort.
b) Calling out a likely domainer is probably equally pointless because they have probably hidden their name and using a throwaway email address.
c) if they are a domainer and you can get their real identity, sure, skewer them online. Its extremely unprofessional behaviour that should not be encouraged.
4. Also remember that even Escrow.com states that a transaction is never guaranteed until the deal is completed. I would have assumed than an agreed-upon escrow.com transaction was a legal agreement, but of course escrow.com doesn't want to get involved in that so they basically state that anyone can back out if the funds/goods haven't changed hands yet. I learned that lesson many years ago when Intuit backed out on buying a domain from me after long negotiations and an agreed upon Escrow transaction for a very significant sale. In the end, I sold the domain for more to another buyer just a year later, so it worked out better for me.
Basically its not worth your time/effort/aggravation unless you know the buyer is a domainer and that they may do this again. Then let'r rip.