Just the other day, I took my Advert and Pop-up blockers down to view a site of a useful but unsuitable nature.
After leaving the site, I for got to reinstate them and run the usual scans. I was rushing off to a game of Curling.
For the next couple of days I could not understand why everything was going so slowly. Then I remembered.
Blockers back up.
Scans run and Ad-ware deleted.
Surfing up to speed again.