The guideline that I use is:
"I know that I have a problem with XYZ when my use of XYZ causes problems."
So regarding the internet, unless and until my use of it creates real-world problems in other areas, I do not view it as a problem.
Should some activity start creating real-world problems, the 3 options I consider are:
1. Cold turkey: Just stop it. This usually fails for me.
2. Controlled use: Limit usage. This usually fails for me.
3. Substitution: Determine what need of mine the troublesome activity is meeting, then experiment with less harmful (or maybe even healthy) alternatives. This usually works for me, though it takes time and patience and being gentle with myself.