Something that we're used to see in China (China Telecom is regularly pissing me off with injected ads), but that I would not expect to see in the US. Though I

Something that we're used to see in China (China Telecom is regularly pissing me off with injected ads), but that I would not expect to see in the US. Though I seem to remember seeing such kind of practice once in San Francisco. What are the legal recourses you have with regards to this type of forced advertisement?