Proposals for network neutrality laws are generally opposed by the cable television and telephone industries, and some network engineers and free-market scholars from the conservative to libertarian, including Christopher Yoo and Adam Thierer. Opponents argue that (1) Network neutrality regulations severely limit the Internet's usefulness; (2) network neutrality regulations threaten to set a precedent for even more intrusive regulation of the Internet; (3) imposing such regulation will chill investment in competitive networks (e.g., wireless broadband) and deny network providers the ability to differentiate their services; and (4) that network neutrality regulations confuse the unregulated Internet with the highly regulated telecom lines that it has shared with voice and cable customers for most of its history.