There are several potential reasons for what you are seeing, but unfortunately I can't tell from the pics. You can look at symptoms under the leaves and for webs (spider mites) that I can't see. Take a look here. The first link is the cached version so you can see the search words highlighted. The second link is without the highlight.
My suspicion would be either thrips or some type of disease since all your peppers are effected. I'd love to know what you find.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.