piling on

Short definition from Wiktionary

Verb

1. 1
   present participle and gerund of pile on

Noun

1. 1
   A fighting tactic wherein multiple people attack another: An illegal strategy wherein players tackle an opposing player.
2. 2
   A fighting tactic wherein multiple people attack another: The process by which additional combatants join an ongoing fight or argument when they think they know who will win so that they will be on the winning side.
3. 3
   A fighting tactic wherein multiple people attack another: The process by which multiple people pick on, complain about or list the faults of their target.
4. 4
   An ongoing increase in a change or phenomenon, such as the popularity of a fad: The steady addition of more problems to an already problematic situation or circumstance.
5. 5
   An ongoing increase in a change or phenomenon, such as the popularity of a fad: Doing more and more (of something), especially when it is inappropriate or problematic, such as by continuing to break a diet