Syniverse, a company that routes hundreds of billions of text messages every year for hundreds of carriers including Verizon, T-Mobile, and AT&T, revealed to government regulators that a hacker gained unauthorized access to its databases for five years. Syniverse and carriers have not said whether the hacker had access to customers' text messages. //

Syniverse says its intercarrier messaging service processes over 740 billion messages each year for over 300 mobile operators worldwide. Though Syniverse likely isn't a familiar name to most cell phone users, the company plays a key role in ensuring that text messages get to their destination.