Here's an interesting article on the Internet by Rav Shlomo Aviner, written in Be-Ahava U-Be-Emuna – Parashat Vayeshev 5770 – translated by R. Blumberg.
The bolding is mine (Momo's):
Everybody knows that the Internet is a great source of woe for mankind. This is the case not only for G-d-fearing Jews and not just for the holy Jewish People but for all people everywhere. True, it has good things in it, information and service sites, and we have our various Torah sites, and it could have been a wonderful tool, but in actual fact it does more harm than good.
It leads to people wasting enormous amounts of time surfing the net for nonsense. It broadcasts cheap, shallow culture. For example, 60% of National Religious youth regularly enter pornographic sites. This being the case, better that it had never been invented, for the fear of G-d is more important to us than information and services, and even more important than Torah learning.
Therefore, if someone asks us whether or not they should bring the Internet into their home, our answer is: No! Don’t do it folks! But if one has no choice due to work, or if someone just doesn’t ask us, there is a partial solution through the various filtering programs: In Israel there are Rimon, Etrog, Iconito, Moreshet and Netiv. All of them are good, and each one has its advantages and disadvantages regarding efficiency and ability to filter. Everyone should choose according to what suits him personally, but a filter program is an ABSOLUTE REQUIREMENT according to Halachah. Such indeed is the ruling that has been handed down: If someone has to go somewhere and he has two possible routes, the involving a river where women role up their sleeves to do their washing, and a more modest route, he is obligated to take the more modest route (Bava Batra 57b).
A second solution is to have password without which it is impossible to open the Internet, with two or three people each possessing part of the password, such that the Internet cannot be used without all of them being present. The illustrious Rav Wosner ruled that the laws of “Yichud” [seclusion with a female behind closed doors] apply here. Obviously, the optimal solution is for a person to become so purified, elevated and sanctified as to view all this filth with scorn. Yet that is not enough. The evil impulse can attack a person from within or from without, as Maran Ha-Rav Avraham Yizchak Ha-Cohain Kook explained (regarding the Talmudic debate over whether the evil impulse is more a fly, which comes from without, or like a wheat kernel, resembling a heart split in two (Ein Aya). Rambam likewise writes: “It is a person’s nature to imitate his friends and acquaintances and to develop behavior and attributes like theirs. Therefore, a person must befriend righteous people and always frequent the wise, so as to learn from their deeds, and he should distance himself from the wicked who walk in darkness, so as not to learn from their deeds. As King Shlomo said, ‘He that walks with wise men shall be wise, but the companion of fools will be broken’” (Rambam, Hilchot Deot 6:1). Thus one should distance himself from the darkness, wickedness and foolishness of the Internet.
There is another fine solution in America which can be used here as well, and it has approbations from the rabbis of America and of Israel. By the way, there is a Kollel director here who accepts kollelniks into his program on condition that they have subscribed to this program. It is called "webchaver", and it transmits a weekly report on all the sites visited by the user, placing at the top, in bold, all the problematic sites entered, that reaches the friend chosen by the user. That friend can be the person’s wife who uses the same computer, but with a different email address. It costs four dollars a month.