Why do people constantly pry into the personal lives of celebarties?

You wouldnt want someone to go through your garbage or reveal your personal information in the tabloids,blogs,newspapers,magazines and on tv shows like tmz and entertaiment tonight so why support the paparazzis industry of spying?Why do you need to know what happened and who is invited at chelsea clintons wedding?Now,I do understand that some celebraties crave attention like the hollywood s:lindsey,parris,madonna and britney and some of the men like when he was alive michael jackson and mel gibson(either that or hes a raging alcohalic maniac).But why are celebraties not allowed to have privacy if they want it?