As a slight aside (sorry, Kane) I guess the same could be argued for caltrops (robotic or otherwise). Ive pondered about having very small and simple robots drive under a robot with low ground clearance (as most are these days) and spring up into a caltrop configuration, lifting the opposition off the ground. Actually being able to drive with it there is another matter.

Its not strictly entanglement (the robot is lifted, not entangled). It would probably contravene the holding rule, though.

I just like the idea of defeating Typhoon with lots and lots of antweights. :-)

--
Fluppet