A add-on to change your IP if you is blocked.
https://addons.mozilla.org/en-US/firefox/user/5792631/
Add-on to check links
https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/?src=ss
http://userscripts.org/scripts/show/9467
Automatically check links from more than 50 file hosts, the script is checking the links in bulk when ever possible, that means maximum speed and low bandwidth.