IT pros may be cranking up their email surveillance strategies, but a host of new threats could pose fresh worries. JPEGs, audio files, and camera phones remain Achilles heels for firms afraid of losing sensitive data. (See Email Gets More Outsourced Options, Here Comes the Judge, and Email Looms as IT Threat.)

Despite the plethora of products on the market for scanning text-based email content, images and audio files are tough to track, according to Vit Kantor, founder of security consultancy Spectrum Systems, which works with a number of banks and telecom firms.

"There is no effective way at the moment to analyze a picture or an audio file," Kantor tells Byte and Switch. "With JPEGs, people can run Optical Character Recognition (OCR) technology over the pictures and see what the information is, but it's expensive."

The image gap in email security is a major issue for firms in the manufacturing and design sectors, where drawings and photos are at the heart of their intellectual property. "There is a gap, just because there are no good [OCR] tools out there yet," says Jayson Hahn, CIO of West Caldwell, N.J.-based manufacturer Merrimac Industries, which makes radio frequency and microwave components. "It’s definitely a situation where it's difficult to say for sure that everything is fine."

Even if the appropriate technologies were readily available, though, Hahn says they may not be practical to use. Merrimac, he explains, would need a full-time member of staff to examine all the image-based attachments his firm sends out and check for false positives.

Email surveillance and archiving specialist Fortiva acknowledges that image-based email security is still a work in progress. "Aside from the overhead of trying to do that work, we haven't found tools and technologies that are that reliable," says Rick Dales, the vendor's vice president of product management.

These sentiments are echoed by email filtering vendor MessageGate, which urges users to look out for large attachments and unusual email patterns. "Do the guys in the mailroom really need to be sending around images?" asks Robert Pease, the MessageGate's VP of marketing.

MessageGate, according to Pease, can block outgoing emails at the gateway until the sender confirms that they comply with corporate privacy policies. This feature, called SenderConfirm, can specifically target emails with images attached, he adds.

For Merrimac, though, blocking image-based attachments would seriously impede the day-to-day running of the business. "If you set up rules by on a per-person and a per-group basis, that becomes another layer of management," says Hahn.

Instead, the exec has embarked on some detective work to make sure that users are complying with his firm's security policies. "You have to look for trends outside of email," he tells Byte and Switch. "Is the person staying longer than they have to? Has their [hard] drive suddenly filled up for the first time in ten years?"

Another technology posing a security hazard is the camera phone, which, as recent events in Baghdad show, can open up a Pandora's box of problems. "One of our biggest concerns is people using camera phones and emailing that information," admits Hahn. "That's a major issue for a manufacturing firm or anyone with government contracts."

The problem with camera phones is that the images can be emailed over the service provider's network, completely bypassing a firm's own email infrastructure. Such is the level of paranoia about this issue that Merrimac has banned camera phones within its facilities.

Camera phones are popping up on the radar of firms outside the manufacturing sector as well. "We wouldn't want people taking photos of customer account information and walking out with it, or emailing it," says John White, MIS officer at Brockton, Mass.-based Harbor One Credit Union.

A camera phone ban may be on the cards at Harbor One. "We have discussed it, but we haven't come up with any policies on that at this point," says White.

One thing, at least, is certain -- email surveillance is going to swallow up a sizeable chunk of IT time in 2007, even without checking images. A recent survey by Fortiva and law firm Pitney Hardin, for example, found that firms are spending an average of 12 hours per week for every 100 employees to review 10 percent of their emails. (See Email Review Can Reduce Risk and Jury's Out on Email Scrutiny.)

— James Rogers, Senior Editor, Byte and Switch