open season 
noun [in singular]
1The annual period when restrictions on the killing of certain types of wildlife, especially for sport, are lifted.Bluewings accounted for the bulk of birds taken, with Peach Point hunters taking about 15 mottled ducks during the brief open season....
- Closed seasons themselves will not actually prevent a population decline unless culling levels are quite low even during the open season.
- Further, the Commission recommended not only an annual close season but also a weekly close time during the open season.
1.1A period when all restrictions on an activity, especially on criticizing a particular group, are abandoned: it’s open season on public figures...
- We need open debate, not an open season on seaside pranks.
- Procrastinating and prevaricating in the matter would amount to sanctioning an open season on minorities.
- Last year, it was open season on the company, but now when you look at the business as a whole, it makes it easier to concentrate on the shop floor.