nowadays, even i use my DA to purchase online at 1am for only RM34.xx (after convert), they will immediately call me to verify.
maybe bcoz online transaction, and at midnight.
same goes to HSBC, i swipe rm9k 1 shot and they immediately call me to verify too.
but if swipe 2k, 3k, they never call
even DA, previously i swipe (err, slot, actually?) my card twice at esso pump, they immediately blocked the card.
usually bcoz of smiles card cant be read (esso, credit card 1st then smiles card. shell, bonuslink 1st then credit card).
so at esso credit card already authorized, but smiles card cant read, so i cancel it.
when i swipe (slot) the DA card for 2nd time, declined!
i immediately call the bank and they told the card had been blocked (afraid for unauthorized use for petrol).
i verify it and ask them to unblocked it.
this happen to me 2x in a same day! i pump once at morning and again at night.
solution: redeem points till finish and apply new smiles card
(my 'damage' smiles card cant be read at petrol pump but no problem if swipe at cashier inside

)
this story happen b4 pbb offer esso/mobil

. This event does not incurred any loss to me but I feel that their the way their system work does not offer any security to us.
I used my MBB CC to purchase a 2K DELL laptop for my gf. The purchase made under her name but paid using my card. That was the first time i made an online transaction. The purchase went off successfully and MBB did not call me to verify the transaction. A few days after receiving the laptop, I found that my card was blocked. So, I call their CS and was told that they blocked my card as they can't verified that I made the purchase. Reason given, they can't reach me through my cell but in actual, there was no call from them. Another few days later, I received a mail from them saying that my card was blocked due to unauthorized online transaction.
The thing here is that they blocked my card after the laptop had already been received and payment being charged to my card. Just imagine if someone misused my card.