About 12 years ago, my Rav said to me that if there had been internet in the time of Chazal, they would have instituted a gezeira or something of that sort, that would make it yichud for a man to be alone with a PC that is connected to the web. At the time I was considering a business to look up things for people in my area (medical, repairs, warrantee info, directions, whatever they needed), who did not have access to the web. I had many acquaintances who were always asking me to print out stuff for them, or would call me for directions because they were lost. I don’t think it was his opinion alone. It sounded like the concept had been discussed among other Rabbonim.
In some communities, long before TAG was born, it was a given that if someone had internet access in their home it should only be located in a central location. And there are families where the password on their internet filter – or maybe the password for the master user account is made up of two parts. The husband knows one half, and the wife knows one half. They set up their computer that only a master account can access the web. That is the way they protect each other from using the computer clandestinely, or changing any protective settings. They both have to be present, and informed when either one of them is going online.
Obviously this only works when the couple are true yirei shamayim, who, as a team are trying to make sure they don’t fall into a bottomless pit of “trouble” when using the internet.