An online crowd can disperse instantly while its target remains in the same body.

A crowd online forms in hours and disperses just as fast, and each participant contributes something small that felt insignificant to them. The person at the centre does not disperse. They stay in one body, in one life, holding the accumulated weight of thousands of small contributions.

Before adding to a pile-on, however deserved it feels, ask what your particular addition changes. Almost always the answer is nothing except the total. Withholding it costs you nothing and is one of the few points at which any individual has any control over the outcome.