Personally I'm of the opinion that power meters and heart rate monitors should be compulsory for all professional bike races, the data kept privately in escrow for cases of suspected cheating.

It's one thing a domestique getting a bit of a sticky bottle from a team car or someone drafting cars back to the peloton after a crash but now we have the specter of mechanical doping hanging over the sport.

At least with power/heart rate data you could compare the cyclist's performance (speed, rate of ascent, etc) with the power measured at the pedals. If someone's power jumps 50 watts but their heart rate doesn't change over time you know something is up.

Some riders have said they'd like to see power meters banned as it affects the tactics of the race. In that case all you'd have to do is hide the live data from the riders.

The water bottle thing. The sticky bottle.

That's just one thing. I bet there's more.

And electric motors