One of the biggest failures when it comes to breaches (aside from not having proper infrastructure & support) is how staff deal with social engineering and best practices.
Although there are many scammers and hackers that are "out to get you", many of them rely on YOU making the first mistake. I've seen far too many companies that didn't have acceptable use policies when it came to technology in the workplace. You hear these stories of companies losing all data because one staff member was browsing some sordid sites or doing something personally they shouldn't have been doing on a work PC. One of our clients was recently hit with a Crypto Virus and lost all data because they all share files via LAN, so all files across the entire network were encrypted. Proper training on opening attachments and best practices would have prevented this. (A staff member opened an e-mail with the virus in it)
Point being, the majority of breaches and security issues that a company has could be prevented by educating staff and implementing policies and making sure staff comply. Some companies go as far as doing pat downs when staff enter and leave the building, and storage media are confiscated unless approved by IT. Others lock down systems so USB storage devices and optical media cannot be used.
You need someone to perform a security assessment and follow through with the recommendations. It may cost some dear $$, but management and staff can sleep better at night.