I've not been able to read all of these messages, but a couple of initial thoughts:
Card numbers are not only compromised with online transactions.
Everytime a card is scanned at a retailer, that retailer's hardware is potentially compromised by hardware or software installed by a dishonest employee. There are safeguards, but they're not perfect. Online is clearly riskier though.
I don't use debit cards. PERIOD. We put all our purchases on a credit card and pay the balance off each month. While I acknowledge that their popularity grows, I still view them as a conduit into my cash accounts. Technically, my ATM card is a debit card, but it's not tied to our main accounts and I rarely even use cash. I may be outdated and old school in my concern, but I feel that the consumer has more protection against fraudulent credit card usage (but I've not reviewed the laws recently).
I would NEVER USE A DEBIT CARD ON AN ONLINE TRANSACTION. Much more risk and protection can be less available if YOU don't have current spyware/virus detection software on your computer. Use PayPal as a safer intermediary and they can debit directly from your checking account. I still use a credit card for online purchases unless it's through PayPal.
Mr. Silver Mom got a telemarketing call where she wound giving out her checking account # (to me, similar to a debit card)...After 9 months, I'm still dealing with the implications, and although I tracked and recovered the $1,000 that was stolen from her to NY, then Canada, then California...I will assure you I had better things to do with my time then deal with that.
JMHO...
If you don't grow where you're planted, you'll never BLOOM - Will Rogers