What use does potassium have?

If they were stealing potassium metal, it may be for a meth lab or to sell it on the black market to people with meth labs. I have included a link that discusses the chemicals found in meth labs, including potassium metal.

I also have given you a link to the Wikipedia article on potassium. When I read that potassium metal reacts violently when exposed to water, I had memories of my high school days, when some boys stole some sodium metal (which also reacts with water) and threw it in the lake to watch it explode.

If you have ever worked hard out in the sun

It reduces muscle fatigue and helps to conduct the distribution of electrolytes.

If you ever work very strenuously and later suffered cramps, Potassium will help to alleviate they're severity and even lessen them.

Bananas are an excellent source. I always have one if I have to work out in the sun(or you can cheat and just have a GATORADE).

Have a look at the link below as this explains uses,benefits,etc:

http://fairfield.k12.ct.us/tomlinson/element/potas...

http://www.megaessays.com/viewpaper/37334.html