If you own a cable modem, expect a substantial increase in your monthly rates if a proposal currently before the Federal Communications Commission goes forward. The FCC is considering levying an additional tax of up to 9.1 percent on the revenue of cable modem providers. In theory, a cable provider is not required to pass the tax increase along to customers, but in practice, companies tend to do just that. EarthLink said last week that it would raise prices because of digital subscriber line (DSL) taxes imposed by state governments. It's safe to assume that EarthLink will do the same thing if a cable modem tax comes along from the federal government. Read more: CNet News.