I prefer to use my "Citi" credit card for all online purchases because
they have a deal to issue you a temporary, one-shot account number
good for a single use. The deal is free to cardmembers, and since the
account number expires after you use it once, then fraudsters cannot
make use of it even if they steal it from a vendor's poorly-secured
e-commerce server. It's only a very small inconvenience to have to
click thru a sequence of webpages on Citi's website to issue you the
one-shot number, but the peace of mind is well worth it.