Query: It has been alleged that Comcast's internet service has done what to customers? 
Context: The company's customer satisfaction often ranks among the lowest in the cable industry. Comcast has violated net neutrality practices in the past; and, despite Comcast's commitment to a narrow definition of net neutrality, critics advocate a definition of which precludes distinction between Comcast's private network services and the rest of the Internet. Critics also point out a lack of competition in the vast majority of Comcast's service area; there is limited competition among cable providers.