I have an LG Optimus L90 from T mobile. I had this problem every since I got the phone. All three pictures I take with the back camera always has the dots whether it is in light or dark lighting.
I think that the 10-posts rule is for posting links rather than screenshots, but anyway, if there are several marks always in the same places in each photo, it suggests pixel failure or similar. If that is the sort of thing you mean, the warranty should take care of it.