Ultrasonic transmissions. UHF

We typically think of them as safe and they generally are.

Over air, etc, used to see images behind objects (Ultrasound) but governments around the world are starting to use ultrasonic technologies and microwave tech as weapons.

There's currently a DEW available to the military that sends direct microwaves at targets to heat up water molecules on the skin and create an instantaneous burning sensation.

Active Denial System

There's also been reports from politicians in China and Havana of "Ultra sonic" weapons being used against them "Havana Syndrome". Some of them experienced measurable amounts of brain damage similar to a concussion after hearing loud and disorienting piercing noises in their homes.

Ultrasonic transmissions have also been used to passively steal information from hard drives. To see what's on your TV screen and to passively energize other types of spy devices through resonance such as piezoelectrics.

In more recent years governments have been using their understanding of UHF to see human shapes in rooms before entry with wifi router signals.

Police currently use certain versions of parametrics as well "LRAD". Used as helicopter loud speakers to both play "curfew tones" at riots and major sporting events such as the Super Bowl as well as to bounce messages off walls at long distances.

Maybe not what you're looking for but it is kinda interesting that the same tech we use for Radio, TV and cellular communication is now being amplified and utilized a weapons tech.