You let other people have copies of your sensitive data and store it online where people can hack into it? {boggle}
Actually, if there were strong encryption [using some passwords and passkeys that were moderately long strings], and if you weren't storing anything which might attract the attention of the codebreakers at the NSA & their supercomputers, then you wouldn't have all that much to worry about.
So I guess the question would be: Does Carbonite offer encrypted backups?