Perhaps you are being sarcasic, but I cannot tell. This is a version of the broken window fallacy[0]. The money spent on the ISPs is now unavailable for netflix (as an example) to spend hiring new people, buying rights to new movies, etc. So it is not a given that this increases the GDP, or that it would do so in a healthy or beneficial way.
[0] https://en.wikipedia.org/wiki/Parable_of_the_broken_window