If you're enrolled to Verified by Visa then you have to enter your password every time you use the card online, so the answer is yes, they would need to use this password too.
Out of interest, why do people use ewallets when you have cards? Never understood it personally, it's not like you pay tax on winnings and you need to hide it...
1) eWallets ringfence your gambling money.
2) Credit cards now charge fees and interest on gambling deposits, and unlike purchases, interest is still charged even if paid off in full when the statement arrives.
3) Credit card companies are blocking more and more gambling transactions because they trigger their automated fraud flags. Most casinos do NOT support "verified by VISA", and this is another reason such transactions get blocked.
4) Debit cards work better, but if compromised, can end up with your bank account getting emptied, which can have a severe knock-on effect on your day to day life, and can lead to bills not being paid and charges mounting up. If your eWallet is hacked and emptied, only your gambling is put on hold, not the rest of your life.
5) eWallet transactions are much faster, especially withdrawals. Cards hold your money up for a couple of days, and where casinos can't refund to your card, they insist on sending a cheque, which means even more delay before you can use your winnings.
6) If your eWallet doesn't have the money, your deposit gets rejected. If you use a card, your deposit may still work, but you will find yourself overdrawn, possibly an unauthorised one, and will be hit by massive charges.
One feature offered by eWallets is actually a security weakness. You can connect a bank acccount to it, and where there is not enough money to cover a transaction, your bank will be charged via a prearranged variable direct debit, rather than your deposit getting rejected. The weakness here is that if your eWallet is hacked, your bank can be emptied too.
Another aspect is privacy. If you use your bank debit card, your bank will know that you gamble, when, and how much. They may also make assumptions using an incomplete model, for example, they will see the debits, but may not be where you receive your withdrawals, so the bank will think you are losing far more than you are.
This data will then count against you if you apply to your bank for a loan or mortgage, even just an overdraft.
In the UK, the taxman doesn't care about gambling winnings, but WOULD care about any AFFILIATE derived earnings, which are usually "laundered" by the affiliate system and can not be differentiated from gambling wins/withdrawals once remitted to the UK.
I am sure that the tax office will eventually figure out what is going on, but at present they are just not geared up to fit this kind of income into the tax regime, hence it is down to the honesty of individual taxpayers to self declare affiliate earnings.
if its bigger then 5 grand i think, its somewere around 20% so i rather keep my winnings at Neteller and use there master card to spend my winnings instead of wire the money back to my account and have the tax man around 
