DOES MICROSOFT HAVE FILE-SHARERS IN ITS SITES?

Microsoft sent out warning e-mail messages this week to people it believes have downloaded portions of secret programming code for the Windows operating system. The warnings are similar to those distributed by the RIAA to users it accuses of illegally swapping music.

If Microsoft decides to join the battle against file-sharing networks, the record biz will have gained a powerful ally in its attempts to stamp out online copyright infringement.

Microsoft could argue that file-swappers are violating trade-secrets laws, which are even stricter than copyright statutes.

Experts say ISPs that don't need to give up the names of their subscribers under copyright law may not be so protected by trade-secrets law.

Microsoft could claim the file-swapping networks share responsibility. So far, the RIAA has been unsuccessful in shutting down those companies.

A Microsoft spokesman insisted the company supports the idea of peer-to-peer networks, though he stressed that trading copyright-protected material was illegal. The company has sued many software pirates in the past.

The company has a big advantage over the recording industry in that it can try to introduce anti-trading protections in the next version of Windows.