Big trouble? To paraphrase someone who never seemed daunted by big trouble..."it depends on what your definition of 'trouble' is". These are pixels where the transistors that address them have failed. That's trouble. Not much you can do, unless there is a warranty that expressly deals with this situation.
Most warranties allow for a certain number of dead pixels. You may be stuck with them until more appear, if they ever do. They can get very specific with how many and if the are adjacent to each other or not.