Sometimes when you set up an account with a company, they'll let you set a question and the answer. Then when you call in, the operator will read the question YOU WROTE and you get to provide the response. This has the potential to be highly amusing if done right:

Q: What the hell is your f***ing problem, sir?
A: This is completely inappropriate and I'd like to speak to your supervisor.

Q: I've been embezzling hundreds of thousands of dollars from my employer, and I don't care who knows it.
A: It's a good thing they're recording this call, because I'm going to have to report you.

Q: Are you really who you say you are?
A: No, I am a Russian identity thief.

Check out a ton more here.

With tweetMyMoney, you can monitor your account balance, deposits, withdrawals, holds and cleared checks with simple commands. And, you can even transfer funds within your account. It’s all available on Twitter, 24/7! And, the best part is, our tweetMyMoney service is free!

(Emphasis mine)

Hello Twitter banking, goodbye money.

Why anyone thought this was a good idea, I don't know. Granted, you can't transfer money to OTHER accounts, only "within you account", but someone who breaks into your twitter account can still get a lot of information about you and move your money around causing you serious overdraft fees.

The issue at heart here is that getting information about your account and moving money around only requires the security of your Twitter account (which isn't to say much). How many people put strong passwords on their Twitter like they do the bank? How much effort does Twitter put into their security?

I think the idea of alerts to your phone is kind of cool, but maybe the bank should have set up its own Twitter-like messaging service instead of using a public one that's a big fat target of bad guys already.