The Personal Pictures Protection Act is being reintroduced, having failed to pass through in last year’s Congress. It threatens anyone with a fine and/or up to two years imprisonment who:
"with the intent to embarrass or cause emotional distress to another person places on a computer photographs of the sexually explicit conduct of that person, so that such photographs are accessible on the internet without the permission of that other person."
In the UK, the Data Protection Act would apply in most circumstances where someone wanted to put such a photo on-line where the subject of the image is identifiable. If it applies, the Act means that prior consent would be required.