Peter Fleischer on the Official Google Blog on Monday:
We’re introducing a method that lets you opt out of having your wireless access point included in the Google Location Server. To opt out, visit your access point’s settings and change the wireless network name (or SSID) so that it ends with "_nomap." For example, if your SSID is "Network," you‘d need to change it to "Network_nomap."
This has got to be a hoax.