Strangest thing I have ever seen, I have been anxiously awaiting a Fedex parcel, and did a Google search from within Firefox for - Fedex Tracking.
I mistakenly replaced the e in Fedex with a 3 - so I inadvertently searched for 'F3dex'. The search results came up, but when I clicked on one of them I found myself locked out of Google and forced to enter a code to prove I was a real person. No other Google searches would work until I proved my IP/PC (I guess) was a real person. Everything works now, but I was temporarily in panic mode, as I thought I had unleashed the wrath of the big G on myself.