These video cameras are a possibly Privacy breaking deal but it does not mean the end of the world. While I hate them, I have to accustom myself to their existence and find other ways out. Even wearing a mask and a hat is still better than nothing at all. There are ways to improvize things on the moment.
How would the 'whole world' know that I used Bitcoin? How would they know me in the first place? Why would that video become known all over the World, does Walmart post their security camera videos all over the Internet constantly?
It's too paranoid. Most of people don't care about privacy and if they care about it, they are mostly not too paranoid like this.
If anyone is paranoid about this risk, they have other choices, other merchants to buy things with other payment methods too. Walmart is not the only place where people can visit for shopping.
Modest privacy protection proposalBitcoin Privacy Guide