From China Digital Space
yī xiǎo cuō 一小撮
Literally a pinch, a scoop, or a measurement equivalent to a millimeter; used figuratively since at least the Cultural Revolution to denote a group of wrongdoers. “A small bunch” appears in official reports on both the Tiananmen Square protests and the Weng’an Riot.
An official report will often say something to the effect that “a small bunch of ‘baddies’ with ulterior motives had a hidden agenda to ‘fan the flames,’ thus ‘deceiving’ the masses who don’t understand the actual situation (一小撮别有用心的人“怀着”不可告人的目的“煽风点火”，而“不明真相”的群众则受其“蒙蔽”). Critics complain about the use of stock phrases like this because they minimize the underlying social factors that lead to disturbances, and portray the aggrieved populace as simply being duped by a small group of troublemakers.
An explanation from Baidu Baike:
Emotions are always incited, the actual situation is never understood, and every crowd is a small bunch. I’ve heard this once, twice, thrice, four times, an infinite number of times. “Bunch” is a measurement. Dust is in a bunch, but dust can’t be bunched up. Salt is also in a bunch. A bunch makes you feel sparse, small, not worth a mention. It’s the tone of voice of the person you love deeply, but who doesn’t love you, beckoning you to come. It makes you feel so minuscule as to be weightless. And yet, except for the Creator, what kind of person can use this measurement? Who deserves to use it? Where there is no justice, there is the small bunch. Where there is no equality, there is the small bunch. Where there is no freedom, there is the small bunch. One small bunch on top of another. A small bunch scattered by the wind. A small bunch washed away by the rain. But if it is not here, it will be there. The people who use this word think it’s the perfect insult. The people who hear this word think it’s the greatest praise. When this word is repeated once, twice, thrice, four times, an infinite number of times, there will be countless small bunches, and then I must ask: in the end, who really is the small bunch?