Are there some civil liberties that people should be prepared to give up in times of war?
What needs to be considered here is whether temporary suspension of civil liberties is sometimes necessary to defend one's nation and in turn defend those civil liberties. For example censorship and the curtailment of freedom of speech during World War Two with campaigns such as 'Careless Talk Costs Lives' can either be seen as necessary to ensure unity and no enemy infiltration or as unecessary intrusion and direction from the state. Some may argue that perhaps one's civil liberties should never be suspended as they are the foundations of democracy. Others may say that to protect democracy sometimes sacrifices need to be made. It might be worth thinking of more recent news items of individuals' rights to privacy versus keeping those individuals safe from external attack.
The famous example must be habeas corpus during the American Civil War.
During World War Two, people in the United States had to use ration cards to buy food, gasoline, etc.
One might want to google executive order 6066 for an interesting example of civil liberties.