American telco giant AT&T doesn’t want to charge femtocell users twice for the same data, but exempting its customers from the second bill could fall foul of US Network Neutrality, says the Public Knowledge blog, which has demanded an FCC investigation into "data cap abuse".
Femtocells are tiny base stations which route cellular connections over domestic broadband to extend coverage, but that generally results in customers paying twice for the data: once to their cellular network and once to their broadband provider, so AT&T decided that customers buying both services from AT&T should only be charged once, which is where Net Neutrality kicks in.