Superstore Cossack

ДА!!!!!!!!!!

Good attempt but that is not how you do it properly :P I am Russian and I know how to do the cossack dance and what I was told is this, The legs must always stick out forward and not sideways, and one leg at a time can make contact with the floor

how do you do the dance

Karfagen is right this is very sloppy. If schupak, the legs go to the front - low knee height very fast or up to shoulder height slower. If preseke, same as above but legs to the side.
Some professional examples
1. Virsky
2. Soviet Army - dance of the cossaks
Also search Hopak. There are lots of good non professional groups. I dance with one of them.

The people behind act like if it were normal. Is it?

It's a British thing - keep looking straight ahead, don't react, don't make a scene, act like everything is OK etc.

I wish I was British. Here in America everyone's like, "YOU'RE DANCING IN PUBLIC? I'M SUEING YOU!"

So you're saying the other fourteen seconds were good then? Lol.
X3

word!

HAHHA Mr.  Badass from the super market XD