Microsoft Corp has filed a lawsuit for copyright infringement against a website operator who it claims has been illegally distributing software that disables the time limit security feature in a trial version of Office ’97. Microsoft said it is unknown how many people got hold of the software, which allows users to continue using the product after the 90-day trial period is over. The investigation is ongoing, but a spokesperson acknowledged that little can be done to track down these illegal users. However, as the low-priced trial offer – in conjunction with Kinko’s Inc – ends soon, there is a measurable limit to any damage. The suit is a civil one and carries a fine of up to $100,000 per offense. Microsoft insists that in future trial offers, security will be looked at more closely.