New York Attorney General Eric T. Schneiderman has launched an investigation into whether local residents are actually getting the broadband speeds they pay for.

Schneiderman’s office recently sent letters to Cablevision, Verizon and Time Warner Cable, informing them that net neutrality advocate and newly appointed senior enforcement counsel and special advisor for the attorney general’s office, Tim Wu, would lead the investigation.

Wu said in the letters that the difference between promised speeds and what customers actually get may be big enough to be labeled deceptive advertising. The letters also suggest that slowdowns may be occurring due to reasons within the operators’ control.

Congestion at key interconnection points could be contributing to slower speeds, the office said. There also exists the possibility that interconnection arrangements may render irrelevant any benefits of that customers would receive from paying for a premium speed option.

The letters also requested a wealth of information from each company including network management and advertising practices as well as copies of all broadband customer complains relevant to the matter.

In a separate statement, Schneiderman said families already pay a huge cost for Internet access in New York, adding that he will not tolerate a situation in which they aren’t getting what they have been promised.

All three service providers have released statements saying they’re confident that they’re providing advertised speeds to customers and vow to cooperate fully with the investigation.