What does Google mean “Unusual traffic” message?

If you search with Google with an asset VPNconnection, sooner or later you will come across Google's “Unusual traffic” message. It may look like this:

More specifically it says: 

Our systems have detected unusual traffic from your computer network. This page checks to see if it’s really you sending the requests, and not a robot. Why did this happen?

Below the message you can see the exact time of the message and above it there is a box where you can tick “I’m not a robot”. If you do, you may be shown one Google Captcha, which must be completed to prove that one is human. If successful, you will be forwarded to Google, where you can search as usual. Sometimes you are forwarded directly without a captcha when you claim to be human.

If you click on “Why did this happen” you are forwarded to a page with the explanation.

That's why you get Google Unusual traffic message with VPN

There can be several reasons why Google displays the message. All are aimed at preventing or at least inhibiting abuse of Google's search engine.

Although unusual traffic may sound suspicious, it is nothing to get nervous about. There is no reason to be afraid that a virus, malware or on the device has arrived. You also won't get the message because you've been hacked.

With VPN the reason is quite simple; namely that you share an IP address with all the other users who are connected to the same one VPNserver. 

Therefore, there can be several people using Google with the same IP address within a short time. This triggers a mechanism in the system to ensure that there is a human behind the computer.

There is nothing dangerous or unsafe about sharing an IP address; it is actually one of the strengths of VPN, that the IP address cannot be associated with individual users.

There is nothing to be afraid of; it is neither illegal nor against Google's guidelines to use VPN. It also doesn't compromise your anonymity, because there's nothing more to it than completing the captcha.