The liability insurance is good to have for shooting in general, and in fact required for commercial shooting in some public places in addition to industrial sites. As our agent explained it, the corporations and agencies want to make sure that if you injure someone on their property, claims will be filed and covered by your policy before the claimant can get around to suing them too, or if they sue both of you, your pocket will get hit first and deepest. Without the policy, you're asking them to assume all liability for your actions, even though they may have minimal control on you. We had our insurance carrier produce a proof of insurance card for our liability coverage, just like the card they issue for auto and health coverage. It's handy to have one of each in your pocket when applying for permits to shoot in parks or signing contracts with corporations.
BTW- For loss to "government action," also think about security forces seizing your camera for shooting pics of bridges, sky scrapers, etc. I had a near miss recently on a contract to shoot a moving train at multiple locations through the mountains. I was pretty proud of myself for mad dashes to get ahead of the train for the first shots, but then railroad security and state troopers rather disrupted my progress. Word had not filtered down from RR headquarters that I would be out and about, and I was stopped. A few phone calls sorted it out, but by then I was too far from the train to get ahead again. Ended up shooting the whole thing over again on a subsequent day, but with phone #'s for the relevant officials in my pocket along with a letter and a copy of my contract.
