We do filter the internet at our YWAM Centre but we try to keep it to a minimum as we want to instill trust and deal with what we would consider inappropriate use of the internet with relationship and discipleship. The areas we filter out are porn, gambling and extreme violence. We also do some DNS filtering that blocks out many of the adverts (especially those that point towards Malware).

The Base here does filter Internet access. But our office is, due to space, not on Base property. In the office we don't filter the access. I personally prefer the not filtering route.
Instead I would prefer more emphasis on training and educating people about the Internet. While it's true that we can prevent other from stumbling with all the things you can find online. But they then still "can stumble" when sitting at home at their computers.

IMHO it's much better to educate people, if they want help them to set up a browser with advertisement blocker and if needed even more security features. As well as checking their general computer safety settings, spam settings for email client, etc.
Of course, that requires of us, as IT minded folks, that we know, at least to a minimum degree, how things are working in the most popular applications and obviously cross-platform. In other words, if we want to be educators we need to educate ourselves first.

My question to ask ourselves really would be, are we doing ourselves and others a favour if we block things. In a sense this is the easy route for us. If it's blocked we no longer need to care about things, incl accessing sites that we don't want people to visit during office hours, e.g. the above mentioned social networks. (I'm ignoring for a moment that there are often ways around it, for the technical minded people, anyways)
But just say we have filtered everything and do that job well and people are protected from any nasty stuff that is out there. This will not help anyone when at home or on outreach. Also not when someone moves on to another location where Internet might not be filtered.

In that case, I guess, we need to ask ourselves if we have failed our brothers and sisters.
To some this might sound like an outrages question to ask. But honestly, if people "want to stumble" there are always ways and plenty of opportunities. A filter in the office doesn't help.
But if the stumble because I haven't educated them I am just as guilty.

That is my opinion, anyways. I don't know if I'm on the right track with that. But this is how I see things.

Thank you Steve and Eagle.

I'm not a fan of filtering, but I do believe that it has it's place.

I have found filtering the Internet to be a real pain to administer, as someone else commented about on my Facebook page about this post. Like Steve said, it also doesn't actually change someone's heart, only their behaviour when they are hidden behind our firewall. Filtering isn't discipleship and although it might "protect" our brothers and sisters, it certainly doesn't help them to grow.

Although this would probably be frowned upon, but I prefer the "Big Brother" type approach of watching. Me and an accountability partner have a program called X3Watch, which is put out for free by the people at XXX Church, that monitors the sites that I visit, but doesn't actually filter the Internet. This I believe can lead to accountability and conversation, which can hopefully lead to personal growth.

We have also used this technique at the last YWAM centre that I worked at. We were using filtering as well as monitoring on our firewall and were able to track down and speak to someone who repeatedly hit filtered sites. I believe that being spoken to about it, and having accountability for it, helps people to grow and mature in this area so that not only their behaviour can be changed, but also their heart about it.

Like Steven said too, if someone knows what they are doing they can usually get around any filters that we put in place anyway ...

I agree that it's better to educate than to use filters, but with content being pushed via ads, misleading articles and so on, I find it useful to have some filtering, like Eagle mentioned before.

Also there's the case of liability, if you have a business internet account for you base and shares it with the residents and students, you may need to cover your back legally and put in place a strong T&C and some Deep Packet Inspection (DPI).

http://en.wikipedia.org/wiki/Deep_packet_inspection