We've all seen chumras that, while we don't agree with them, we wouldn't denigrate others for using them. Then we've also all seen chumras that people have that arise out of a lack of basic halachic knowledge.
Then, of course, there are the ultra-silly chumras - those that arise out of that special combination of a lack of basic halachic knowledge and a lack of common sense. My wife provided me with just such an example.
She was in a supermarket buying items for Pesach, along with just about every other Jewish woman in Brooklyn. While there, she observed a woman who
-- lined her shopping cart with plastic
-- very meticulously made sure that every item she put into her cart was in a plastic bag (aside from the plastic that she lined her cart with)
-- if an item fell on the floor, she not only didn't put it back in her cart, she didn't even want to put it back on the shelf so that others could take it (we're talking about pre-packaged stuff, not produce) because it might have become chametz.
With my perverse sense of humor, I told my wife that if I was there I would have gone over to her and said "Psst! You know that those bags were in a box that was touched by truck drivers who ate chametz the day it was delivered," or "Psst! You know that those bags are touching the shelves which touch the floors which touch other shelves that have chametz on them!"
(To be honest, I wouldn't have done that; there's no need to further confuse the already confounded.)
I shudder to think what Pesach cleaning at this woman's home consists of. I'm willing to bet that if she had just a little more knowledge on the halachos of chametz, she could make her life (and the life of her family) so much easier.