It's quite safe, the robots you see in the video have a maximum output that is quite gentle, enough to push small and medium sized toys through a well lubricated passage-way but otherwise harmless.

We have stronger devices that will also be supported day 1 on the beta, and these devices have their power and stroke length defined in the driver software. These more powerful devices aren't so much robots though, just single axis articulation and no bidirectional feedback -- good enough for accelerometer control though where there's no channel for feedback anyway.

ALSO, remember in encounters with humans communication is key! make sure they know what you want and how, just as if they were really there.