If I ever get the message "Access to URL has been blocked" surfing the web over 3G, I'll call customer service to ask if the phone number has filters applied. Here is the short story that leads to this conclusion.
We have a Samsung Captivate smartphone running the Android v2.1 operating system. Browsing the internet worked over both wireless and the 3G data network. Then came a day when 3G browsing no longer worked but wireless did. Neither research nor 'random walks through solution space' (as a friend is wont to say) yielded a solution so we went to the AT&T store for help. Even though they had not heard of this problem they were helpful and attempted some resolution to no avail.
After 20 minutes of failed attempts they still did not give up but rather brainstormed and checked assumptions. One such assumption was that the phone account itself had the proper permissions to browse the web over 3G. Since this capability worked before and we had not requested it to be disabled, it didn't seem likely that this was a problem. However, a call to customer service revealed that the phone line was indeed filtered in a way to block data, including web access, over 3G. This configuration was incorrect and never requested, but a plausible explanation is that when we requested data blocking for our daughter's line my wife's line was inadvertently blocked as well.
So, if you are getting the "Access to URL has been blocked" message, see if the line is somehow filtered.
Here are some troubleshooting observations and actions we tried that failed.
- All internet activity was successful when connected to a wireless network.
Some internet activity was successful when not connected to wireless
but going through 3G
- Examples are weather, local news
- These activities had a phone application associated with them
- Reset browser settings
- Put into flight mode for a few minutes then return to normal mode
- Remove battery then put it back
- Use a different browser