Technically, it isn't a "No Plastic Bag at Stores" Law. It's a "The Store Can't Provide You With a Plastic Bag" Law.

Fun Fact: You're still allowed to use plastic bags...as long as YOU provide them for yourself (or for others). Want to? Here you go:

350 Shopping Bags For Your Shopping Convenience

Be ready for some fun, though. Some cashiers will try to be all Super-Eco-Warrior and claim "Hey, you're not allowed to have those anymore. And we're not allowed to let you use them." (WRONG.) Some will be like "Hey, where did you get those? We were supposed to get rid of them all!" (Sure, dumb dumb, but that doesn't mean we had to.) And, of course, you'll have fellow shoppers who see what you've done and say "Hey, that's cool! Got any extras? These bags they're giving us/making us pay for SUCK!!!"