rayden54: A) Most debit cards act like credit cards anyway-meaning you can use them as such. My ATM card (not a debit card) is still set up to let me overdraft.
B) "The money is immediately deducted from your current account." If someone steals it, and manages to use it online (where they often don't ask for the PIN), that money is gone from your account. Now, yes, you'll get it back (same with a credit card), but in the meantime your rent money's gone. Oh, and even when they do give you the money back, you usually end up paying the overdraft fees.
A) Overdrafts are evil. In most cases the interest rate on the overdrawn cash is so high that you should avoid it except when you really really need something, but you currently don't have enough money. It's very easy to fall into a vicious overdraft spiral: the next month's paycheck covers the previous month's overdraft, but the costs of living create another overdraft, and so on, meanwhile the bank makes profit from the interest rates. Most shops now permit you to pay for their goods in multiple instalments, so that's a safer option.
B) Isn't it easier to steal money from a credit card? All you need is the physical card and the signature – the former can be easily stolen, while the latter can be forged, so it's easy to make unauthorised transactions involving thousands of dollars before the theft is discovered. With a debit card, you can only withdraw money or pay for goods if you know the holder's PIN, or with an ID card in the bank. The ATM may have been tampered with to steal your PIN, but I try to avoid that by drawing money only from ATMs in public places that are under supervision round the clock.
Of course, people who write their PIN on the back of their debit card deserve theft for tempting fate.
Now, the problem I see with credit cards is mostly ideological. I feel uncomfortable taking a product I'll be paying for significantly later. It feels like a mini-debt that is coming to bite me in the ass. With debit cards I have already paid for the product on the spot, there will be no charges arriving in my mailbox later. It may be irrational, but I believe in that Latin proverb:
clara pacta, boni amici.