review bomb
organized or coordinated effort by a group of people to flood an online platform or website with negative reviews or ratings for a particular product, service, or content
en-US/ˌɹivˈju ˈbɑm/
en-GB/ɹɪˈvjuː ˈbɒm/
organized or coordinated effort by a group of people to flood an online platform or website with negative reviews or ratings for a particular product, service, or content