Martian mice (aka Green environmentalists) have bestowed upon us Americans the 21st century "environment friendly" toilet with its latte flush -- the ones that kindly leave presents for other guests using the restroom and that have to be cleaned twice as often because not all residue evacuates.
To battle this movement, ahem, may I recommend that you begin flushing not twice, but thrice, on each restroom visit? Hell, even if you just go in to brush your hair or teeth, just reach over and push down the handle and know that you'll, by damn, use as much water as you wish in your toilet.
Don't stop there. Be sure to mention said activities whenever you suspect you're around aforementioned Martians. You know who they are: pale, unkempt, angry, vegan-skinny, ghoulish. I find them often in the organic section of my grocery store.
I like to say something like, "Man, I can't believe I've flushed my toilet 14 times today, even though I've only used the restroom three times. Isn't that awesome -- all that wasted water? You gotta love it!"
Be sure to make the last statement while looking right at the Martian, so you can enjoy the full effect. Be warned, some of them are too stupid (well, actually, they all are, but you know what I mean) to catch your drift. They think you're being scatological. Just ignore the poor stupid soul and move on to the more "savvy" Martians, who understand both your meaning and intent.
Bask in their scowl and sneer, and be sure to tell them that you will be visiting the store's restroom shortly to flush all the toilets multiple times to ensure that copious amounts of water are wasted.
I know, I know. Seems like a lot of work, but not really. It's no more difficult than talking about Jesus being a homo when you're around Christians or saying that ObaMao wears panties when you're around Lefties.