In the past, I had complained about problems with the URL blocking in v4.8 (http://forum.avast.com/index.php?topic=46625.0) and later requested that a placeholder not be shown in the web page because it screwed up object placement in the web page sans blocked content (http://forum.avast.com/index.php?topic=45874.0). I don’t recall if it was via forum discussion or a trouble ticket or e-mail from Avast support but I was told that the URL blocking feature was going to disappear in v5 - and it did. Now I see it came back in v6. Yay! Hope it works.
I could use URL blocking by subscribing to a DNS service, like OpenDNS, that let me block on domains (creating a far shorter list than, say, using the ‘hosts’ file which has to include an entry for every host at a domain since hosts are specified there, not domains). However, I’d have to create an account at OpenDNS, update my blocked domains list there, and install their DNS updater client so they would know by my current IP address as to which account its settings would apply against my DNS request. Too much hassle, plus other users in my household would complain about domains that I blocked using OpenDNS (used by the router so it was common to all hosts in my intranet). This lets me decide on what domains to block but just for my host. My decisions won’t affect others.
Because the URL blocking feature in v4.8 was lost in v5, and because OpenDNS was too much hassle to setup (plus there were behaviors with their service that I didn’t care for, like redirecting to a search page on a failed DNS lookup), I used the InPrivate Filtering available in IE8 (along with a registry edit that made IE8 always enable the InPrivate Filter on its startup). Alas, there is little documentation on how to compose the XML file used to specify the blocked URLs and what there is conflicts with itself regarding regex-like syntax. It’s worked okay and I figured out how to use the regex syntax but there are still sometimes problems with using it. Just enabling the InPrivate Filter mode in IE8 with a completely empty block list (and disabling the threshold that blocked sites over a certain reference count) could cause a site not to work properly. I don’t know why but just enabling the InPrivate Filter (with no blocked sites) causes some sites to not handle some of their code properly (get script/object errors). So hopefully I can transfer the block list from the XML file for the InPrivate Filter to the URL blocking feature now returned in v6 of Avast; however, it looks like I’ll have to manually migrate each entry (click Add, copy another site, repeat) instead of just populating an input file or registry entry read by Avast for its URL blocking list.