I've just started getting this message when searching using Google. I'm using a 3BB Indy connection in Chiang Mai. No problems with duckduckgo or any other websites.

This usually pops up when Mr Google sees a lot of searches coming from the same IP address and assumes it's a robot doing the searching.

Are you using a VPN or similar? Try without it.

Almost always generated by the use of a VPN (especially one of the free ones)

Don't some ISP's also somehow group Google requests, making it appear that they all come from one source?

Lots of ISPs are starting to use NAT now - I don't think that will help somehow.

IP4 addresses are running out.

http://www.theregister.co.uk/2015/09/24/arin_ipv4_interview_ipv6/

What seems unusual to me: it shows an IPv6 address?

What seems unusual to me: it shows an IPv6 address?

Which resolves via Neustar to UK2-ltd suggesting a VPN is in use as our OP (says he) is in Chiang Mai.

Yes I have had the message when using a VPN, Google suspects someone is

using your account from another country,nothing to worry about.

regards Worgeordie

One should also remember many Thai ISP numbers were, at one time, associated with huge volumes of junk/spam mail which led to many being blocked.

I am uncertain about the current situation.

I had forgotten I was using my proxy server in Firefox last night and forgot to disable it afterwards. Thanks for the helpful answer.

Lots of ISPs are starting to use NAT now - I don't think that will help somehow.

IP4 addresses are running out.

http://www.theregister.co.uk/2015/09/24/arin_ipv4_interview_ipv6/

you can't NAT two LAN machines for different customers. They would be stealing each other's ports.

Think about 2 customers willing to accept connetions on port 80