Frustration, anger and desperation have led to a series of wildcat strikes.

挫败感、愤怒和绝望引发了一系列自发性罢工。

《柯林斯英汉双解大词典》

Korea's chaebols, for example, have been slow to restructure and their workers have staged wildcat strikes.

CNN: FROM BAD TO WORSE

South Africa's mining sector has been hit by a series of wildcat strikes, which have cost millions of dollars.

BBC: South Africa strikes: Sacked platinum miners reinstated

Last year, wildcat strikes and violent unrest over wages spread to a number of mines across South Africa, the world's largest platinum producer.

BBC: South African miners wounded in rival union clashes