Freelancers: are you using liability insurance? Which one?

I noticed recently that after the Iowa caucus app fail people generally seem more worried about dangers of poor app design and the tone of these conversations makes me think immediately of lawsuits if someone hacked the app I worked on.

Question to all the freelancers in the room: do you have a liability insurance? And if so, which one are you using? Is there a reason why you chose the specific one?