A US federal court is hearing arguments by BT which claim that it owns the patent on hyperlinks and is due licence fees for their use.
But Judge Colleen McMahon warned that it might be difficult to prove that a patent filed in 1976 still applies today. She suggested that the contested invention "was already outmoded by the time it was [ratified] in 1989".
BT claims to have forgotten about the patent until last year when it was discovered during a routine update of the company's 15,000 global patents.
In its submission, the telco said that every hyperlink used on every US website is using intellectual property the company patented and should be subject to a licensing fee.
Should the case against internet service provider (ISP) Prodigy, the first target of the lawsuit, be successful, BT could challenge other US providers. A Prodigy spokeswoman said that the company does not comment on ongoing litigation.
Gartner analyst Debra Logan explained that the lawsuit forms part of a larger BT strategy to get the most out of its intellectual property.
"Corporate legal departments often pursue a strategy of defensive patenting," she said. "The mere prospect of this occurring indicates how more aggressive enforcement of patents by large IT and telecoms companies could disrupt business for firms that use their technology."
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