USB Scanner

From Slashdot: apparently police in the UK are seeking USB devices to scan hard drives for evidence of illegal activity. It's already the case that if your computer is seized then police have the right to thoroughly search your hard drive for any such evidence. So this device would only be cutting down on the number of police man hours needed for such a search.

I wonder, however, if a consequence of such a convenient device for the job might be that such searches were conducted much more often. Does this raise any ethical issues? Is one subject to a privacy intrusion if one's computer hard drive is scanned by computational algorithm, and no resulting scrutiny by a human being takes place?