Vegans
Now, a lot of things have already been said about vegans. Basically they will not consume/use any products derived from animals. (see here) However, in this day and age, that is practically impossible.
Just for fun, I have made a list of some common, every-day items that are derived from animals and therefore should not be used by Vegans. There is also a list here.
Plastic is made from petroleum and natural gas. (information), which is based on organic (animal and plant) compounds
Vegans are not unanimous about ex- or including insect products.
This just baffles my mind. I would not be able to do without many of these things. I mean, even the ends of shoe-laces are often plastic. Going to the supermarket would become troublesome as well, as many carts or baskets use plastic.
It is practically impossible to live in the modern world without using animal products. So, apparently, every Vegan you meet has to make tons of concessions every day.
Just a thought.