Sending card details in plaintext.
Any expats based in Europe renewed their passports recently?
Do the bunch of outsourcing thieves[1] based in Paris still force you to do this as the only[2] method of payment they'll accept?
Dunno which Civil Servant decided to remove the responsibility from the various embassies and set that up instead, but with that track record of sheer fucking idiotic incompetence they're probably a Permanent Secretary by now.
[1] With the extortionate markup they charge on return postage, the markup on the usual passport costs and the fact that, if you call them, they bill your credit card, per minute, on top of the premium rate number they force you to use, that is the correct word.
[2] They're based in France so, while there is some electronic payment method available, this doesn't work outside France as it's uniquely French, as per usual there.