Sharing a warning: Clicking away yesterday my computer screen turned red, screeeeeeeching noises went off, a warning sign appeared that my computer had been “compromised” that instructed me to call a 1-877 number IMMEDIATELY so that Google Support could help restore my computer. Nothing I tried would stop the screeching or change the screen.
The screeching continued for what seems like an hour but probably was 5 minutes. Suspecting the worst, that my computer had been hijacked, I manually turned it off. When I turn it on again it was back to normal.