We're told how to use the internet in excess (7)
I believe the answer is:
surfeit
'excess' is the definition.
(I know that excess can be written as surfeit)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for surfeit that I've seen before include "it's more than one needs" , "having had quite enough" , "Fustier (anag)" , "excessive amount" , "stuff, once" .)