intellectual property and technology law are still relatively young as far as law goes. If I were an aspiring lawyer I would make this my area of expertise.
According to this website:
"Taking images from third-parties. The simple rule is, "Don't steal someone else's images." The moment an original image (or string of text) is fixed on a hard drive for the first time, it is protected by copyright. Any unauthorized copying of a protected image is an infringement of the creator's copyright, unless the use falls within one of the very limited exceptions to the copyright law, such as "fair use." In most cases, it is unlikely that the incorporation of an image into a commercial web-site would be considered a fair use."
The last line of the quote says it all. If you wanted to pursue it you probably would have a legal precedent to do so. However, the time and money spent would of course not make any sense whatsoever.
Another good question is if Dave Feldberg could have any legal issue with you for taking his picture and using it as an avatar.
According to the world intellectual property organization:
"There is no general legal requirement to obtain someone’s authorization to take his or her photograph. However, there are situations where photography can infringe on important social interests such as national security, protection of children, right of privacy, etc. Most of these situations are strictly controlled by national laws and regulations. Irrespective of the legalities, there are also some things a photographer should not photograph for ethical reasons. Certain photographs of people may amount to exploiting the persons concerned or misrepresenting the truth. If you, as a photographer, know the law and one’s legal rights, you will also be in a better position to find solutions that minimize your legal risks.
Often, you may be free to take a photograph of a person, but the way the image is used may give the person shown in the photograph a right to take legal action."
Pretty sure you're in the clear.
However, Voodoo better have his permission...
"Many countries recognize that individuals have a right of publicity. The right of publicity is the direct opposite of the right of privacy. It recognizes that a person’s image has economic value that is presumed to be the result of the person’s own effort and it gives to each person the right to exploit their own image.
Under this right, you could be liable if you use a photograph of someone without their consent to gain some commercial benefit."
Part Time Internet Lawyer
I'll send you a bill