http://www.bbc.co.uk/news/technology-18643134

The short version is that they use cheap equipment ( sub $1,000 ) to create a fake GPS signal to confuse the drone.  This could range from crashing it in to something like a building or the ground or misleading it to another zone for combat.

Civilian GPS is no encrypted, I wonder how well the military version is?

It’s always best to have these steps written down, so here it is for your gmail account.

http://knol.google.com/k/the-c-man/how-to-recover-a-hacked-or-compromised/3p9k5zywla4ku/7?pli=1#When_you_reclaim_Your_Account

This is also a good reminder to ensure your account recovery settings are up to date, and make sure to include a SMS  number.

Unfortunately if you are not in your account when something like this happens you are already too late, once your password is reset it may take a while to regain access to it.