There is a long, thin, rubber-y line wrapped around/connected to the water line pictured below.
Other angle:
The piece in question is loosely hanging via a zip tie on my main water line about shoulder height and can be moved up/down easily.
They aren't, and they better not. The old FCC was vigilant about protecting frequencies and hams will sometimes even be the ones who find the offender and turn over the information to the authority. The fines are not cheap.
We practice this with foxhunts and capture the flag activities.