Hackers equipped with wireless PDAs are skulking around some corporate campuses, looking for chinks in wireless networks as part of IBM's ethical hacking services. But in these days of souped-up security, they could encounter more obstacles than just overly secure networks. There are concerns they could be cornered by increasingly vigilant security officers who aren't aware of their mission, which is often known only to certain executives at customer sites.

"So far, that hasn't been a problem," says Dean Douglas, general manager for wireless E-business services at IBM. Besides, Douglas says, "The contracts stipulate that our people have a 'get out of jail free' card."

Hopefully, any guards they encounter aren't the kind who ask questions later.