The federal government, vastly extending the reach of an 11-year-old law, is requiring hundreds of universities, online communications companies and cities to overhaul their Internet computer networks to make it easier for law enforcement authorities to monitor e-mail and other online communications.

The action, which the government says is intended to help catch terrorists and other criminals, has unleashed protests and the threat of lawsuits from universities, which argue that it will cost them at least $7 billion while doing little to apprehend lawbreakers. Because the government would have to win court orders before undertaking surveillance, the universities are not raising civil liberties issues.

The order, issued by the Federal Communications Commission in August and first published in the Federal Register last week, extends the provisions of a 1994 wiretap law not only to universities, but also to libraries, airports providing wireless service and commercial Internet access providers.

It also applies to municipalities that provide Internet access to residents, be they rural towns or cities like Philadelphia and San Francisco, which have plans to build their own Net access networks.