i live in Maryland, an I've seen that too. On the particular bike that I saw, the whole frame was wrapped, and CO2 cartriges were partway wrapped in the tape. This is not just one or two, there was at least three on the seat tube, and another three or four on the top tube.
It was completely blacked out though, with black four-spoke spinergy wheels. The rider too, was blacked out, with a black halter-top/sports-bra thing and black booty shorts, with a black helmet with a black visor covering her face. An odd person...The theory going around out school is that she is either a movie star incognito, or a really fit woman with a horribly scarred face!
The electrical tape could've just been due to the fact that she's a weirdo though, and she just thought that it would look cool