I understand that when I visit a web site they will send a cookie to my computer. What I don't understand is this: I go into safari preferences and get rid of several or even all of the 1100 cookies on my computer. Hours later they are all back even though I have only gone to a few web sites that have nothing in common with most of the cookies. How do these cookies find their way back to my computer and How can I keep these unwanted cookies off without shutting off cookies altogether