LinkedIn recruitment is different. If someone contacts you via LinkedIn, then they've already seen your photo and are interested regardless. There's little or no way to prove that someone even saw your profile on LinkedIn and then passed up contacting you for a job.
In the case of DeveloperAuction, I'm assuming that if you have a photo, then the potential employers are going to see it. If a 45 year old with similar qualifications as a 25 year old doesn't get offers from the same companies as the 25 year old, it opens up the potential for lawsuits -- this might be over-simplifying. I'm not qualified to comment on how much standing a lawsuit like this would have, but it's certainly happened in similar situations before. That's why photos are a no-no in recruiting in the U.S.
In the case of DeveloperAuction, I'm assuming that if you have a photo, then the potential employers are going to see it. If a 45 year old with similar qualifications as a 25 year old doesn't get offers from the same companies as the 25 year old, it opens up the potential for lawsuits -- this might be over-simplifying. I'm not qualified to comment on how much standing a lawsuit like this would have, but it's certainly happened in similar situations before. That's why photos are a no-no in recruiting in the U.S.