"It was most unlikely (in fact, it is nearly impossible) for a number to be stolen while been transmitted - from your computer to their computer."
If they didn't have a secure site it could be stolen. So it might be that the site wasn't as secure as it should have been.
"Cancel the card and have it reissued. Send an email to each of the hotels and advise them that you number was taken and suggest that they may want to double check their systems for security."
Have already done that, thnx
"And, finally, the number could have been taken six month ago and only now is being used. "
Right, but suspicious that as soon as I use it to make reservations is when it is being fraudently used.
"A secure browser does not prevent some clerk from giving your number to his friend or entering it into a compromised hotel computer."
My error, I should have said "a secure site" from which the number cannot be seen.
I should be getting the card in a couple of days. The week-end slows things up.
Then I will make calls and this time I will ask the name of whoever takes the number. In case it gets taken again.
But I like the Citibank idea. I am going to check into my bank and see if they do something like this. Sounds like a good idea.
Thanks all for the input.