Without knowing which (or how many) browsers you use, and what search engines you have loaded/available, it's unlikely anyone can offer much comment on problems specific to them.

You might have a problem with your modem or router, but only a few of us might know what you're using there. Problems with the device(s) OR just a bad cable between any two things connected could cause false signals.

A possibility that could be common to almost everyone could be corruption in your USB controller(s), since most people use USB connected mouse and keyboard (even if they're wireless you probably plug a relay into a USB port(?)). A bad battery in your wireless mouse could contribute.

Too much beer spilled on the keyboard is a possibility?

Too much beer in the operator could also be suspect.

Malicious activities by Chongo are unlikely, since that would interfere with the keystroke logget he installed on your machine several months ago; although since he was rather irate at the time he may have screwed the setup.

John