[zackboe]

"With respect to your complaint that Cox intercepts and injects our own data in order to display alerts, etc, we note that browser alerts are a method Cox utilizes to bring customers’ attention to important information that may affect their Internet experience."

They'll also appear if you're nearing your data allowance or if their email service (that you probably don't use) is undergoing maintenance. When I last asked, there is no possible way to opt-out or disable these.