[rosser]

I think that would be more them packaging their algorithms into a (preferably free) smartphone app, which (optionally) silently collects "anomaly signatures" until it's on a trusted network, where it uploads its findings for analysis. (It's probably dangerous in some places to do anything that might overtly indicate you're onto "them"...)

EDIT: Based on another top-level comment, someone's already running with a similar idea.