Religion, Nationalism, Patriotism, Political, Commercial, Science, Society, Rebel, even Passion etc.
All of these things can be poisoned to inflict damage to others, even take others lives. For the most part all you have to do is give yourself to a cause whether it's Christianity, Texas, America, Sony, Navy, anywhere. If you give yourself wholeheartedly to a cause without mindfulness, without understanding of consequences that may happen to you and around you, without basically a conscience or moral ground, without your Identity. Then you become a tool just like the tool you follow.
Ideologies and Cultures are not bad things, but they always need to be audited, to be challenged, because time can make any philosophy out-dated and that should always be made aware. Rules are needed, but also needed are rules to change because seldom any rule will be indefinite and true to all walks of life or all situations.
At the moment in life I'd argue that the biggest thing we need in life is tolerance for the things we don't understand or accept and patience to learn. There is probably more but at the moment I am in the same mind as a friend of mine.
The interest is full of extremists in all categories, and in social media sites You can see these battles and complaints and wars all over in right and wrong, the faith vs the atheist for example since that's always popular, and neither party is any better when they devout to some extreme. But when this starts to infect the real world, when people are becoming more and more assertive in this extreme choices of judgement, of discrimination, of profiling, then the world doesn't begin to feel safe, it begins to feel like a cold war waiting to ignite.