One thing you can do is configure you etc/hosts file to outlaw a whole load of adspam and tracker pages. This is fairly easily done.The lists to block are available here. If you use Windows go to Windows32/etc/hosts and copy and paste the list above into it (you will have to run as root/administrator to edit this file). This blocks access to the sites. It's a long list - it took a long time to compile (and thus demonstrates the extent of the problem). When you have done it your hosts file will look something like this...