I lost my wallet once and those that found it used my credit card to buy something at Home Depot in another Province (I live in Canada) but Equifax fixed that for me so I didn't have to pay anything.
I got "hacked" by a clerk a few years ago because I used my credit card. He had some device attached to the payment machine and could hack people but then again my bank got quick into knowing someone tried to replicate my card and everything got fixed.
Even when you go and try to retrieve money from the ATM some people try hard to hack into your cards.
I've been a customer of Amazon and Microsoft for Xbox Live for ages and never got hacked. Never did Microsoft tried to empty my bank account. Both are online stores and I feel more secure with them than using my credit card in real life.
Also it makes things so much easyier on Xbox. You don't have to do it but I personally think that your fears are unfounded. Also you could always enter your info and remove them afterwards.