The best way to deal with personal data security is to act like your information has already been stolen. We all know the data breach stories but the reality is you can't really stop it from happening to you. The mere fact it could take a company a year to even realize they had a security breach means you are not in control. Stop acting like you can prevent your data from being accessed and instead act like it has already been stolen.
Check your accounts at least every other day. Use an aggregation tool so you can go to one site rather than a bunch of sites. Tracks your credit cards, banking accounts and investments. We provide our clients with eMoney to aggregate their data but you could use Mint or Personal Capital to do similar stuff.
Sign up for a credit monitoring service. I personally use MyFico and LifeLock.
Will all this keep your data from being hacked, breached or stolen? Nope. But, it will at least nip it in the bud before it becomes a major problem. Bottomline, be vigilant but not fearful.