Google's new Desktop Search could prove to be the biggest government invasion of privacy of all time. The new tool lets you store your desktop data on Google servers. So when the feds come with a subpoena (or without one, as they frequently do), they'll be able to search through your PC's files.

The technology behind the new features is certainly clever, and there's a great deal to be said for it. If you store your data on Google servers, you'll be able to do a search on that PC wherever you are. So if you're traveling, or at another PC, you get immediate access to your data.

But that comes at a serious price. Google says that your data will be kept private. But keep in mind that Google also complies with most subpoenas from the government, and so it may be forced to turn over your data to the feds or other law enforcement officials if they come calling.

The other issue, of course, is whether Google will be able to keep your data safe from snoops and hackers. It has a very good track record so far -- but who knows what the future holds?

This is a bad enough problem for individuals. But it's far more dangerous for enterprises, because sensitive corporate data is housed on many PCs in an organization.

There's plenty else to like about the new Google Desktop, although I still think that Copernic Desktop is a far better searcher.

So if you do install the new Google Desktop, make sure that you disable the "Search Across Computers" feature --- doing that will keep your data only on your own PC.