It’s mostly been examined as the nexus of the world’s wealthiest nations and drawn some skepticism for being hosted in Pittsburgh. But the recent G20 Summit, also saw enough protesters that police forces were apparently bused in from as far away as Arizona and Florida. For most of the protestors, particularly the 200 who were arrested, it was an up-close introduction to some fascinating new police technology.

Aside from the usual bean-bag guns, flash grenades, and tear gas, the G20 also saw the American premiere of the Long Range Acoustic Device, or LRAD. Mounted on armored personnel carriers, the new devices can send a warning message to its target from a fair distance away. And if that doesn’t work, the device can then transmit a deterrent tone, an overwhelming amount of sound pressure that can basically incapacitate anyone in its path. The LRAD is big, bulky, and not energy efficient, but it certainly does the job of altering behavior without killing anyone. However, known as the Scream, it does unleash a sound that at close range can be 50 times greater than the human threshold for pain.

If the LRAD doesn’t work, although it should, the Vehicle-Mounted Active Denial System, or V-MADS, should do the tricks. Another big and bulky device, this one sends  an electromagnetic beam that gives its target a debilitating heat sensation. With $40 million in research over the past decade, the Active Denial System may even be deployed to Iraq.

Throw in the conventional methods of crowd control and the Pentagon’s upcoming microwave pain-infliction system, which is said to be an airborne version of other active denial systems, and protesting is becoming more harrowing while potentially becoming less lethal. At least you can have a front seat for some fascinating, new, and incredibly painful technology.