Amid cyberattacks, ISPs try to clean up the internet

If your computer’s been hacked, Dale Drew might actually know something about that.He's CSO (chief security officer) at Level 3 Communications, a major internet backbone provider that's routinely on the lookout for cyberattacks on the network level. The company has linked more than 150 million IP addresses to malicious activity worldwide.That means all of those IP addresses have computers behind them that are probably involved in distributed denial-of-service attacks, email spam, or breach