I'd say human contributed greenhouse gas emissions are the main limiting factor for the earth's carrying capacity for human lives. We're already experiencing many more severe climate related weather events and the problem is only going to get worse each year.
I'm actually for us -- especially in the west -- to significantly reduce our carbon footprint and consumption. My personal consumption habits are well-below the average in the west. I think hedonistic consumption is a hollow pursuit. But, I understand that most people will not voluntarily reduce their consumption habits.
The earth has a carrying capacity of less than one billion people if those people have a USA level of consumption. How would we deal with this problem if people stopped dying or had their lifespans increased dramatically?
6. At least in the USA, ISPs can sell your browsing habits(DNS lookups, connection end-points) to third parties. A VPN that doesn't sell this data protects you from that level of snooping from the ISP.