"Texting is growing faster than email on mobile devices," said PJ Gupta, CEO at Santa Clara, Calif.-based Amtel, Inc. "There are employees using WhatsApp to send information to clients. We don't know what servers that information is going through."
According to a survey by HeyWire, Inc., another provider of secure enterprise messaging, 70 percent of corporate employees send messages for work -- and 50 percent of the time, they're sending messages to customers.
In fact, over 33 percent of business texters say that they've closed a business deal via this channel.
"It is really important to secure that texting," said Gupta.
However, he could not point to any major breaches that involved text messages.
According to the 2014 Verizon breach report, internal actors accounted for about 10 percent of all breaches, and, of those, about 11 percent -- or 112 breaches total -- involved the mishandling of data. But that involved everything from taking data home on USB sticks, to emailing documents to a personal account, to writing down customer credit card numbers on paper.
According to Gupta, even if actual losses aren't significant, there are still compliance concerns, especially for the finance, health and law enforcement industries.
However, he could not point to any regulatory actions relating to text messages, and admitted that they currently fall into a gray area that may, someday, draw the attention of regulators.
"Companies need to be prepared for when it is," he said.
Other security experts had a broader perspective on the issue of text messages.
"CSOs can't afford to ignore the reality that text messaging is a valid communications channel in the business world today," said HeyWire CEO Meredith Flynn-Ripley. "It's a channel that is only going to continue to grow in the mobile-centric world we all live in."
But it's no more dangerous than email or any other type of business communication, she added.
"What is dangerous is if your corporate data retention or BYOD policies don't consider text in the mix," she said.
Text messages just the tip of the BYOB iceberg
Unencrypted text messages could potentially pose a problem, but it is a tiny one compared to everything else that a personal smartphone could do in the workplace.
"The reality is that a lot of corporate users configure their personal smartphones to do things like check their e-mail, log onto corporate employee only services and access two-factor authentication services," said Adam Kujawa, head of malware intelligence at San Jose, Calif.-based Malwarebytes Corp. "If an attacker were able to install malware on said smartphone they could obtain information like e-mail credentials, corporate contacts and then of course any kind of juicy info they could get from the e-mail itself."
Text messages are also just the tip of the app iceberg.
In addition to the SMS and MMS messaging provided by the mobile phone company, there are also messaging functions in many other applications -- such as Facebook Messenger, WhatsApp, Apple iMessage, Google Hangout, and Skype. Many games, forums and other types of online communities also allow users to send private messages to one another.
"Enterprises need to protect the data that is used by apps and how it can be shared from them," said Andrew Blaich, lead security analyst at San Francisco-based Bluebox Security. "If they solve the problem at the root, then all other vectors of attack will be minimized."
There are bigger things to worry about
Employees determined to leak company secrets have plenty of options.
For example, they can just pick up their personal phones, make a voice call, and tell the secret information to their outside contact. Or they could write it on a sticky note.
" Just today, I saw an ex-employee of a company having lunch with current employees," said Mike Lloyd, CTO at Sunnyvale, Calif.-based RedSeal, Inc. "But somehow, CISO's are not rushing to bug every restaurant in town. You just write policies against foolish behavior, and you do your best to train people."