Yellow Dohickey on TDF Bikes?

Zog The Undeniable writes:

Werehatrack wrote:

It's a tracking device used to ensure that none of the riders tries to
take a shortcut. If the bike leaves the course for more than about a
minute, the piece explodes, throwing purple dye around.

Couldn't the riders wear explosive collars as in "Total Recall"?

Or like Brian Wells wore in Erie PA while robbing a bank in 2003.