I live in Iowa and I don't know what the restriction is all about. I can go to my local Wal Mart and buy Aqua Potable, or local sporting goods store and buy a Katadyn or MSR water filter. I went to a bigger sporting goods store this weekend and picked up my first package of MP1 tablets.

I don't know why there might be restrictions, but I can safely say that campers and the like aren't making secret border runs to buy water purification products...just fireworks <img src="/images/graemlins/grin.gif" alt="" />