A MiFi device connects directly to the cellular network, and lets devices connect to it to use that connection for internet access--sort of like a wireless router whose WAN interface connects directly to the nearest cellular tower.

And some of these things are TINY. I think I mentioned that I've seen one that's about half the size, but twice the thickness, of a credit card. But I can detect every one of them from a central console due to their WiFi signal, and try to triangulate their location on the buildings' floorplans. If I need to, I can disrupt the WiFi communication so any device associated with these MiFi devices gets disconnected over and over again.

But, for now, all I'm doing is going to each signal I find, taking down the name of the owner and cube number, and putting that in a database, with an association with the device's MAC address. Just in case policy ever changes in a way that prohibits these devices...

So I'm gathering that this particular issue may be more of a productivity issue than a security issue. And we'll be able to control how USB devices are treated on any endpoint on the network pretty soon. So the MiFi 'problem' may become more of a moot issue.

A question: I've installed dd-wrt on all my routers at home, and I've noticed a feature that allows an access point to connect to another access point as a client. Is there a way that MiFi devices could do the same thing? I'm asking because of our workplace WiFi infrastructure and all...