I trust real money more than this kind of solution. Think about when you lost your phone or it is stolen. You life is messed.
HRm, I don't know about phone but..
Credit cards/debit cards stolen:
1. Have to keep an eye on bank account/Credit card account in case number is grabbed.
2. have to call the banks and report it and deal with hassling with them
3. have to report it to the police (because if nothing else the banks are going to want it).
4. You aren't liable for the charges (or only some in case of some debit cards).
Cash:
1. You'll know your cash is gone when you go to use it.
2. DOn't have to call banks.
3. Can file a report if you wish (but no banks to want the report).
4. That money is gone gone gone.
I'll take the card. It's more hassle but at least I'm not out the money (or at least all of it in case of some debit cards <- your mileage may vary here, that's why some people say just use credit over debit. Credit cards by law are subject to giving you some protections, debit cards only do so if they feel like they need to to get you to use it).