Unfortunately, personal info can be easily attained by anyone these days. Much easier than anyone would care to think.
I work for a bank and any one person that is employed by the bank can access any and all personal info for anyone that has an account or has had an account at our bank. In retrospect, we as a bank do everything we can to keep your personal info confidential, and I can't think of one incident where a customer's info was compromised as a result of carelessness on our part.
However, the lax security measures that most major businesses employ these days can be directly related to customers info being compromised. Just in the last year we've had major issues with both TJX (the company that owns TJ Maxx, Marshalls and a number of other clothing stores...) and Hannaford's supermarkets compromising our customers personal info. In both instances debit transaction histories were stolen (including debit card numbers) via a stolen laptop (TJX) and a hacked transmission of transactions (Hannafords).
Was this the banks fault? Not at all, however we felt the repercussions and thus lost the confidence of our customers that were effected by someone else's carelessness.
My advice? Invest in a credit report, if not monthly then yearly at the least, whether through an online company such as freecreditreport.com or annualcreditreport.com or through your local bank if possible. If you feel your info has been compromised, file a report with the 3 major credit reporting companies, TransUnion, Equifax and Experian.
There are a lot of ways to protect your credit and personal info, a lot of people just fail to utilize these tools. They're worth it in the long run, though.