The suit was filed in California Superior Court, Marin County, by attorneys representing Hariett Judnick and seeking to represent the public in the state of California.
New York-based DoubleClick declined to comment. "Typically we do not comment on any lawsuits going on at DoubleClick," a company spokeswoman said.
The lawsuit alleges that DoubleClick employs sophisticated computer tracking technology, known as cookies, to identify Internet users and collect personal information without their consent as they travel around the Web.
The suit comes just a month after DoubleClick completed its $1.7 billion acquisition of Abacus Direct, a direct marketing company. The merger was unsuccessfully challenged by privacy advocates, who worried that the deal would chip away at the fragile privacy of consumers on the Internet.
"Based on previous experience...these class-action lawyers follow privacy advocates like ambulance chasers," said Jason Catlett, founder of Junkbusters, a resource site for privacy-protection measures. "I think it is inevitable that we will see more suits filed."
Catlett said he believes that DoubleClick's strategic plans for Abacus are at this point deeply entwined with compiling consumer profiles.
"I don't know how DoubleClick can back down after having painted (itself) into a corner with the (Abacus) acquisition," he said.
Earlier this week, DoubleClick confirmed it is forming alliances with Web sites across the Net to create a network that will allow it to track surfers' personal data and shopping habits.
Although Net users aren't informed or aware that they are receiving a DoubleClick cookie unless their browser is configured to alert them, they can disable the cookies at DoubleClick's Web site.
Until recently, DoubleClick's policy was to not connect personal information with its widespread cookies.
"Even if DoubleClick provides warnings, such warnings give no protection to many unsophisticated Web surfers," Ira Rothken, an attorney representing Judnick, said in a statement. "One wrong click and the originally anonymous cookie becomes a window into that consumer's private life."
The suit alleges that DoubleClick has "represented to the general public that it was not collecting personal and identifying information and that it gives privacy interests of Internet users" the utmost importance.
The suit also alleges that after its acquisition of Abacus, DoubleClick combined the power of its cookie technology with the information it acquired to create a "sophisticated and highly intrusive means of collecting and cross-referencing private personal information without the knowing consent of Internet users."
Lawyers for the plaintiff are requesting an injunction against DoubleClick that would stop it from using technology to collect personal information without prior written consent of the Internet user. The suit asks for a clear and simple method by which Net users can destroy collected private information. It also asks that DoubleClick be required to destroy all records obtained without a consumer's knowing consent.