In another comment I mentioned a client company that had a locked down default-block web proxy in place. During a site visit with the two developers I was working with I discovered two surprising things:
1. The conference room where I was working had two ethernet ports; one went through the proxy, and one had a clear line to the internet. Apparently this was a common setup in the offices.
2. Everyone was required to use IE, and to use the proxy-managed ethernet port. But I develop using Firefox and I didn't get blocked by the proxy, regardless of which port I used. It turned out that the proxy had to be set up on the browser. The developers were granted admin rights on their machines so they could manage the proxy settings for IE but no one else could. However most people had the ability to install Firefox or Chrome, which would give them proxy-free access to the internet. They just had to know they could do it, and then not get caught doing it.
Turns out this was all about control rather than security; they had a real problem with people spending time on websites they shouldn't have been on, during time they should have been working.
1. The conference room where I was working had two ethernet ports; one went through the proxy, and one had a clear line to the internet. Apparently this was a common setup in the offices.
2. Everyone was required to use IE, and to use the proxy-managed ethernet port. But I develop using Firefox and I didn't get blocked by the proxy, regardless of which port I used. It turned out that the proxy had to be set up on the browser. The developers were granted admin rights on their machines so they could manage the proxy settings for IE but no one else could. However most people had the ability to install Firefox or Chrome, which would give them proxy-free access to the internet. They just had to know they could do it, and then not get caught doing it.
Turns out this was all about control rather than security; they had a real problem with people spending time on websites they shouldn't have been on, during time they should have been working.