Have you ever come back from holiday and realised that handful of text messages was going to cost you three quid? Well, just be happy you're not the guy who blew £20,000 downloading TV shows on holiday in France.
The name for that gut-crushing feeling is 'bill shock', and Ofcom, the telecommunications regulator, is hearing from more and more people who are suffering surfer's remorse, thanks to sky-high data roaming charges.
They include a person who bought a 5GB limit data-roaming card prior to a trip to Austria and received a bill for over £4,000 -- it turned out that the operator had a 50MB roaming limit. Another guy used a mobile to surf the Web in France and got dinged for £400 for 15 minutes of access.
Ofcom has released a handy PDF guide, and a video, below, for those of us who are as likely to read a guide as we are to have read our mobile contracts in the first place.