Google 403 Forbidden – First Prove You are a Human

I have come across this weird Google behavior. Almost every time I open a new browser window and search for something in Google I get this page which says ” but your query looks similar to automated requests from a computer virus or spyware application. To protect our users, we can’t process your request right now”

I am wondering if this works on specific queries, or advance search operators. I have no clue.