It wasn't foolproof, but this unique Firefox add-on filters and hides specific kinds of comments posted on YouTube.
YouTube Comment Snob is easily set through its Options menu. Using check boxes, you can apply filters for comment content you want to hide. The options include comments that contain no capital letters or only capital letters, as well as excessive punctuation. You can also specify how many misspellings you are willing to accept. The option to hide comments with excessive capitalization was too similar to the option that hides comments with only capital letters, and we didn't think both were necessary. The final setting filters out profanity. These are pretty broad strokes, and the definitions for each filter aren't spelled out. We would have liked the option of at least viewing, if not editing, the filter parameters.
The program was largely success, although we found some comments that we felt should have been hidden were left unchanged. For the messages it worked on, the user only sees a simple "comment hidden" message. YouTube Comment Snob works for the most part, which may be enough for those who feel some relief is better than none.