(someone's) snowball effect

Translations
эффект снежного кома (кого-то)
The small protest quickly turned into a massive rally, thanks to the snowball effect.
Небольшой протест быстро превратился в массовый митинг благодаря эффекту снежного кома.
Definitions
The phrase '(someone's) snowball effect' refers to a situation where a person's actions, decisions, or circumstances cause events to build up and grow in significance or impact over time, much like a snowball rolling down a hill gathers more snow and becomes larger. It highlights how small beginnings can lead to much larger consequences, often beyond the person's initial control.