4. Web-based apps can be portals to leaks and thieves
A common behavior that leads to a lot of security problems includes the use of Webmail or allowing workers to access music-downloading and file-sharing services from the company network, said Marcus.

Such Web-based apps bypass your security filters, as in the case of Webmail, or open a channel to the outside that may carry viruses or worse into your organization.

And if your employees take work home, these risks are magnified. If they use your computers and also do personal activities over the Web, those computers could be compromised, Marcus said. If they bring the data home -- via e-mail or a thumb drive -- they risk it getting lost or stolen.

All of these problems can be avoided fairly easily through enforcement of policies that require the use of secure mail clients over VPNs or encrypted channels (in the case of e-mail), or not allowing users to install apps on their work computer or copy data to removable media (in the case of taking work home). Much of this can be managed through security policies and systems management apps. One difficult channel to block is the use by employees of e-mail to send themselves data, though encryption can help.

5. Hoping the worse doesn’t happen only makes it worse
Nobody wants to have a data breach, but you need to act as if one will, advised Kevin Mandia, chief executive of Mandiant, which specializes in post-breach analysis services and software tools. Every organization can take steps to lessen the impact of a breach once it happens. Unfortunately, most companies wait until it is too late to test or even create their response strategies, he said.

Every company should record the data flow, from who had access when to what systems used the data. But few do, Mandia said. "There's no question, the most common error we see is failure to document what happened," he said. "People hire us and the first thing we ask for is any related documentation that people already have. Most often, people will hand terabytes of data and no formal documentation. Technicians stink at it, and lawyers don't mandate it. So in almost every incident, we go in and ask them what happened and the response is the sound of crickets chirping."

6. Avoiding or diluting response leadership makes breaches worse
Companies also seriously inhibit their ability to respond to breaches by failing to appoint a single leader or small team to spearhead efforts to respond to incidents and chase down important details.

In many firms, the process devolves into a game of pass-the-buck, while others involve so many people in the breach response effort that they actually become a hindrance to the related investigation.

"We often respond and no one is in charge, no one wants to be, and as a result, no one knows what dedication of resources to give the incident in terms of money, tools, or technologies, and no one person individually can balance their day job with the amount of resources needed to handle a major incident," Mandia said.

"On the flip side, some companies now bring too many people to the decision-making table while still trying to respond. We show up and we're immediately briefing 12 people -- and 10 don't need to be there," he said.