Im-Perfect infringement in the US
I see that Perfect 10 are now suing Microsoft in California for copyright infringement by virtue of including in its search results unauthorised images of Perfect 10's content which link to the full-sized images for free (presumably therefore by-passing Perfect 10's payment mechanisms). This follows similar cases against Google and Amazon earlier this year which Perfect 10 lost (but which are being appealed).
In principle, creating unauthorised copies of images is clearly an infringement of copyright. However, Perfect 10 lost the earlier cases on the basis of the US copyright defence of "fair use". This is a statutory defence, said to be based on the US constitutional principles of freedom of expression. It permits the unauthorised use of copyright works where such use is "fair" in the circumstances taking into account factors such as "the purpose and character of the use" and "the effect of the use upon the potential market for or value of the copyrighted work".
The US exemption for fair use is much broader (and gives the judge much more discretion) that the UK equivalent defence to copyright infringement of "fair dealing". This permits unauthorised use for a specific and narrowly defined list of reasons such as non-commercial research, criticism and private study. Leaving aside any potential jurisdictional issues in bringing proceedings in the UK, surely Perfect 10 would have stood a better chance of obtaining their injunction over here as it is difficult to see how Google or the other search engines could have fitted their thumbnails within the fair dealing defence. On this point at least our copyright laws are more pro-author than those in the US.