A WebmasterWorld thread has one SEO claiming he is no longer able to use a VPN to track Google search results in a different country.
This SEO is based in Singapore and uses a VPN to access the U.S. Google search results. He sad recently that stopped working and Google is detecting he is using a VPN and thus showing him the Singapore results.
I've been seeing some unsettling behaviour recently with accessing google.com through VPNs, presumed it was a bug at first, but it's been present for over 2 weeks now.
In order to get accurate USA positioning I have to view google.com though a USA VPN, I have access to 9 servers (a mix of a commercial VPN offerings and my own private servers... not a VPS, a private server!)
I have used this approach to get USA rankings for a few years now, but in the past few weeks I've noticed that google is redirecting google.com visits to google.com.hk or google.it or google.co.in. Essentially identifying my VPNs as Chinese, Italian or Indian.
If it is any help my servers are located in New York State, Texas and Los Angeles. All but one now being identified as a random non-USA visitor.
Thinking that google.com may have a way to identify that I'm visiting through a VPN I even used lynx on one of my Texas servers to access google directly, so no VPN involved, google.com still detected me as chinese.
No one else in this thread confirmed the issue, but he said people are complaining about it in the member only SEO Book forums. I cannot verify that simply because it is member only and I cannot discuss what is going on in there.
Have you noticed this issue? I don't see how Google can detect you are accessing a computer in the U.S. and figure out to show you different results on a machine within the U.S. Something doesn't sound right here.
Forum discussion at WebmasterWorld.