Other names to appear on the lawsuit, filed in a Virginia district court, include the Washington Post, Dow Jones, Tribune, Gannett and Knight Ridder. They claim that Gator places ads on behalf of advertisers on their websites without permission, and then keeps the revenues generated by the ad sales.
The lawsuit is reported to describe Gator as "essentially a parasite on the web that free-rides on the hard work and investments of plaintiffs and other website owners".
Gator has defended itself against the allegations. In a statement, CEO Jeff McFadden said: "We're highly confident that the allegations made by the plaintiffs are utterly baseless."
The statement goes on to accuse the companies bringing the lawsuit of wanting to "slow the momentum of a competitor with a more effective marketing platform". Gator says it may counter-sue.
The plaintiffs are seeking an injunction to prevent Gator for continuing with the strategy, as well as seeking repayment for all the revenues it has gained using this method.
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