[pns]

If hard drive is encrypted (and like most companies like Google, almost certain they would be), then you wouldn't be able to get much unless you someone got them to disable screensavers/computer sleep and keep the machines on for awhile

[Phlarp]

Law enforcement has specific tools that do precisely this. Google "USB mouse jigglers" for more info.

They also have gear that can splice into the power cord of a live machine without interrupting the flow-- the combination of these two devices allows them to seize unlocked computers and keep them accessible while taking custody of the machine.