Blacklisting specific tags from an input format instead of whitelisting I need a filter for the "Full HTML" input format that allows me to strip specific tags. I want to allow all HTML tags, except the ones specified in the input format options.

I am using Drupal 7.
You can get that functionality out of the box with the HTML Purifier module.

Once you've installed the module, go to the admin/config/content/formats page, choose the text format you want to edit, and select the "HTMLPurifier" checkbox. In the settings below, quite a bit further down the page, you'll find the ForbiddenElements textarea:



That's where you need to put your disallowed tags. It's probably worth looking at the rest of the settings to make sure they match up with your expectations (there are a lot of them though, HTMLPurifier is pretty configurable).