open season
noun
in sing.
1- the annual period when restrictions on the killing of certain types of wildlife, especially for sport, are lifted（尤指对作为运动而猎杀某些野生动物取消限制的）开放季。
1.1
- a period when all restrictions on a particular activity, especially on attacking or criticizing a particular group, are abandoned or ignored（尤指对攻击或批评某团体等特定活动取消限制的）开放季：
it's open season on public figures.
现在是批评公众人物的开放季。