The paparazzi are done being mad at Mariah Carey's ultra-diva antics -- now they're trying to get even.

Mimi's been unofficially placed on a paparazzi blacklist after breaking unwritten fame game rules at a CD signing event last week.

After Mariah showed up two hours late (bad), sprinted down the red carpet (even badder), and wore sunglasses on the red carpet (huge no-no), paparazzi nation decided to unofficially boycott the singer -- that means no pictures, no coverage, no love. Surely, she will plummet into obscurity.

We're hearing the photogs are planning to ignore the singer as long as it takes to prove their point ... or until Mariah wears another slutty outfit (tomorrow?).