Paypal Playing Games

I was just blessed by a sizeable sale of 19-covers on HipStamp from a buyer who has bought from me before on two occasions, each time with a similarly-sized order. Instead of getting the usual 'Notification of Payment received' email from PayPal, I instead received a message stating:

"We've placed a temporary pending status on this transaction.
To comply with government regulations, PayPal is required to review certain transactions. This payment is currently being reviewed and we will complete this process within 72 hours. This review only involves this transaction and does not affect the use of your PayPal account for other transactions.
Sincerely,
PayPal"

Has anyone come across this <expletive> before or know what the <expletive> its all about?

DOCGFD ----Don't worry about it ,it could be anyone of a number of things . It could be the buyers tax problems ,it could be a breach in his bank that transfered the money . Someone could of used your customers name for illegal activity .There are so many things going on and you will never get the right story .

PayPal owner is ebay. So they ptotect more the buyer then the seller.I quite ebay because of this approach.

Why do you say they're "playing games" when you don't actually know why you got this message? Isn't that misleading?

Selling a large number of items to the same person in short order can trigger it.

There is no current relationship between PayPal and ebay. (And the current relationship between these two independent companies is pretty rocky.) Both are public companies, both are owned by shareholders.
Don

Drew -
That would be why I'm asking here, in case anyone else has had this happen and can explain why. My apologies if my euphemism doesn't work for you...please forgive me...and thanks a bunch for your input...very helpful...

Rog - Since this is the 3rd or 4th time this buyer has bought a large quantity off of me, it seems it would have made more sense if this had happened the first time around, or is it just arbitrary, 'luck of the draw' for some algorithm to be triggered? I'm more curious as to what 'government regulations' could be involved. Its not like this transaction involved thousands of dollars. I just spent the last hour backing duplicate listings off of ebay (I do this manually these days since the automatic synch system has disappointed in the past). What if for some reason this transaction falls through or is cancelled by the buyer because of PayPal's action? Re-listing everything as a result would be a huge inconvenience and loss of time.

Did you sell any covers from any place like Cuba or Iran? That would send up a red flag with PayPal just like it does with ebay. I don't know if Hipstamp reports the listings of what's sold to PayPal. Sites like Delcampe don't.

Nope. Good thought, but the covers were all US, GB & India, and nothing from embargoed countries,

I had a transaction or two put on hold in the past, for no apparent reason.
Got the money in the end.
Very puzzling at the time, as I really couldnt see what the issue might be.

My buyer has no clue why this happened so I called them. Apparently this is a random thing and it was just our bad luck that this transaction was selected. The bubbly PayPal child could only tell me that they are supposedly required to do this, and when asked what exactly they are looking at, could only tell me "uhhh….everything."