It's tradition and while the vast majority of fans don't interfere with the riders, a few, mostly drunk, do get in the way.

The television cameras make it seem worse than it is.

The riders say the encouragement on the climbs helps as long as they stay out of the way.

When Lance hooked a bag and went down, he didn't blame the fan.

I have wanted to strangle some of the fans, though. And I've seen several riders pushing them away and one fool that got run over by a motorcycle.