In its effort to uphold the 1998 Child Online Protection Act (COPA), the U.S. Department of Justice is leaving no stone unturned. Its widely reported issuance of subpoenas to Internet search companies AOL, MSN, Google, and Yahoo is just the tip of the iceberg: The government has demanded information from at least 34 Internet service providers, search companies, and security software firms.

Responding to a Freedom of Information Act request filed by InformationWeek, the Department of Justice disclosed that it has issued subpoenas to a broad range of companies, including AT&T, Comcast Cable, Cox Communications, EarthLink, LookSmart, SBC Communications (then separate from AT&T), Symantec, and Verizon.

Asked which companies objected to, or sought to limit, these subpoenas, Department of Justice spokesperson Charles Miller declined to comment, citing that the litigation was ongoing. He also declined to comment on the utility of the information gathered by the government.

The documents presented to InformationWeek reveal that some companies did object to the government's demands. In an E-mail sent to the Department of Justice last July, Fernando Laguarda, an attorney representing Cablevision Systems Corp., characterized some of what the government was asking for as "overly broad, vague, ambitious, and unduly burdensome."

In a letter sent to the Department of Justice in August, Joseph Serino Jr., an attorney representing Verizon, voiced similar objections. However, he clearly states that his objections are routine and intended to protect the company.

The one exceptional objection he cites has to do with the sensitivity of the information sought. Serino said Verizon Online is concerned that documents might be forwarded to people working for entities hostile to Verizon Online, or that are suing the company, including the Justice Department itself and the American Civil Liberties Union.

Verizon didn't respond to requests for comment.

The subpoenas were issued between June and September 2005. Beyond AOL, MSN, Google, and Yahoo, the only other search engine subpoenaed was LookSmart.

It's likely, however, that the government's interest in LookSmart stems not from the company's search engine, but from its ownership of Internet content filtering software company Net Nanny.

LookSmart declined to comment about the information it was asked for and the information it provided. EarthLink likewise declined to comment.

The bulk of the subpoenas were directed at Internet service providers and makers of content filtering software. The effectiveness of filtering technology is a critical issue in the COPA case. If the Department of Justice can prove that filters fail to shield minors from explicit material online, COPA may well be reinstated.

The full list of companies subpoenaed by the Department of Justice includes: 711Net (Mayberry USA), American Family Online, AOL, AT&T, Authentium, BellSouth, Cablevision, Charter Communications, Comcast Cable Company, Computer Associates, ContentWatch, Cox Communications, EarthLink, Google, Internet4Families, LookSmart, McAfee, MSN, Qwest, RuleSpace, S4F (Advance Internet Management), SafeBrowse, SBC Communications, Secure Computing Corp., Security Software Systems, SoftForYou, Solid Oak Software, SurfControl, Symantec, Time Warner, Tucows (Mayberry USA), United Online, Verizon, and Yahoo.

The subpoenas directed at security software companies asked for a substantial amount of information, including any and all documents that fall into 29 separate categories, including the kinds of content filtering products or services offered, the number of customers using those products or services, how users configure their filters, how filters get updated, R&D spending on such products, the methodology used to generate blacklisted or filtered sites, and pretty much any data gathered that relates to the use of filters.