Yes, it's completely justifiable. I'm sure that no one likes the feeling of their privacy being violated. However, if they truly cared, they would not have been sharing their information and images on a very public computer network. I think between the UK and US security team actions, people are finally beginning to realize that if you want to keep something private, you need to keep it to yourself.
People have a right to privacy, the government should not be allowed to go through a person's private web cam and harvest their photos. The only way that they should be allowed to is when the person is suspected of a crime and the pictures can help prove them guilty or not guilty.
There is no justified reason that Yahoo had the "right" to so this. It is not only a terrible breech of privacy, it questions the entire concept of being safe at home, not to mention government spying. If the government go a hold of these webcams, there could be some serious lawsuits.
No, it is not justifiable that the UK captured millions of images from people's webcams on Yahoo. Those are images that the people using the service believed were private between themselves and whoever they allowed to watch their camera. There is no reason a government can justify spying on a person without an warrant.
It is never justifiable to record or take pictures of someone in their own home without their knowledge. This act is deplorable. If a regular person was caught doing this they would spend lots of time in jail. The government should be held to those same standards as well. It is not right.
Government access individual webcams without the owners' permission a violation of privacy. Furthermore, images obtained as a result of such efforts should not be admissable in court because the entire nature of the act is very reminiscent of George Orwell's Big Brother in the novel 1984. If we are reverting to a type of society in which we are all constantly under surveillance, then we are giving up too much individual freedom for the sake of civilization.