Users of the Internet take for granted their ability to access all Web sites on an equal basis. That could change, however, if Internet service providers started discriminating among content, to make more money or to suppress ideas they do not like. A new "net neutrality" bill has been introduced in the House, which would prohibit this sort of content discrimination. Congress has delayed on this important issue too long and should pass net neutrality legislation now.

The Internet, at least in this country, is a remarkably unfettered medium. If you type in the domain name of a large corporation or a small blog, a government Web site or a radical political party, the pages are sent to your computer with equal speed. Like a telephone line, an Internet connection does not play favorites - it simply transmits the words and images.

I.S.P.'s, the companies that connect users to the Internet, want to change this. They have realized that they could make a lot of money by charging some Web sites a premium to have their content delivered faster than that of other sites. Web sites relegated to Internet "slow lanes" would have trouble competing.

This sort of discrimination would interfere with innovation. Many major Web sites, like eBay or YouTube, might never have gotten past the start-up stage if their creators had been forced to pay to get their content through. Content discrimination would also allow I.S.P.'s to censor speech they do not like - something that has already begun. Last year, Verizon Wireless refused to allow Naral Pro-Choice America to send text messages over its network, reversing itself only after bad publicity.

There are several good net neutrality bills in Congress. One in the House, sponsored by Edward Markey, Democrat of Massachusetts, and Charles Pickering, Republican of Mississippi, would give the job of preserving net neutrality to the Federal Communications Commission. A Senate bill sponsored by Byron Dorgan, Democrat of North Dakota, and Olympia Snowe, Republican of Maine, takes a similar approach. This month, John Conyers, Democrat of Michigan, and Zoe Lofgren, Democrat of California, introduced a bill that would allow the Justice Department to bring antitrust actions against I.S.P.'s that violate net neutrality.

Using the F.C.C. is the more direct approach, since an agency could step in quickly to correct violations. An antitrust suit is a much more elaborate step for the government to take, but also adding net neutrality to the antitrust law would give the I.S.P.'s a strong incentive to respect the democracy of the Internet.

Cable and telecommunications companies are fighting net neutrality with lobbyists and campaign contributions, but these special interests should not be allowed to set Internet policy. It is the job of Congress to protect the Internet's democratic form.