What are these wiry protrusions on a TV antenna?
Looks like they're what's commonly referred to as lightning rods, though their purpose is to provide a means to dissipate and equalize the charges that may build up between clouds and the earth and thus prevent a lightning strike from occuring.

Those little bristles provide for the charges to leak off.  Tiny points at the end of a piece of metal is an effective way to to this.  Notice how most "lightning rods" are pointed at the tip?

Another key is that the cable those bristles come off of are clamped to what looks like a big grounding cable, that runs down the mast to earth ground.