Aside from being the first known predecessor to the inevitable T-800, the Alacom/tmsuk T-34 security bot doesn't seem that formidable. But pay no mind to its Hoover-esque appearance—the T-34 will take you right out.
The T-34 is essentially a remote-controlled security drone. It can be controlled from afar—by mobile phone if the operator chooses—and putter around a building at a healthy 9.5kph, sending visual data to its remote pilot. This data is kind of the point of the T-34, as it is intended to be deployed in situations where a security system alerts, but doesn't provide enough actionable information to be useful.
It's not just a surveillance drone either; the T-34 will start throwing net if you don't cooperate. It seems like it ought to be pretty easy to escape a 10kph, cell-controlled robot, but I'm not one to discourage Cyrax-esque net-throwing capabilities no matter where they crop up. [Dailymail]
UPDATE: Now with video, thanks to BotJunkie.