CNN has an article about privacy concerns about Google. We can read that Google, because of its size and new services that store user data, may be a good target to stole user data from.
I don't deny, that there's such risk. Let's think, however, what's more dangerous: possibility that your data is stolen from Google or your bank (especially one of those using only password, no one-time passwords or tokens) or your telecom? The data Google has about you is nothing when you compare it with the later two. Chances are...well...similar.