Think about what "a picture" means. How many kilobytes is that? How much memory do you have in your Arduino? Now do you see the problem? Sure an Arduino can TALK to many of those cameras, but there is SO MUCH data in even a very LOW-RES image that there is no way Arduino can DO anything with that data except to IMMEDIATELY send it somewhere else, perhaps to save it on an SD memory card, or send it to a PC or Mac, etc.
what other interesting things can I do with an Arduino?