Just now, I went for a walk in the company of
some steel wire and a magnet.

I checked 50 bikes and 10 hade
non-magnetic handlebars.

The non-magnetic handlebars were on MTBs or
more modern-looking bikes.

(To do the same thing with only the naked eye
would have required a shaman of the
first order.)

--
underground experts united
http://user.it.uu.se/~embe8573