Warning! Warning! (Sorry, just watched a "Lost in Space" marathon. Picture my arms flailing wildly.) YouTube may be home to countless cutesy cats playing the piano, but the video-streaming service definitely has its seedy side.

Specifically, YouTube doesn't filter user comments, and some of them are downright atrocious. I've seen hate speech, profanity, and ridiculously excessive punctuation. Okay, that last one's merely annoying, but the fact remains that YouTube can expose your kids to decidedly inappropriate language.

Thankfully, there's an add-on for that. YouTube Comment Snob for Firefox filters undesirable comments from YouTube video pages. It's not foolproof, but it definitely helps.

The tool blocks comments based on one or more criteria: all capital letters, no capital letters, excessive punctuation and/or capitalization, and so on. It can also kick in when it detects a certain number of spelling mistakes.

Most importantly, YouTube Comment Snob filters comments that contain profanity. If that amounts to snobbery, then a snob be I.

This is a must-have add-on for parents trying to protect their kids from the Yahoos (the "Gulliver's Travels" variety, not the search engine) of the Internet. YouTube is supposed to be fun; now it can be a little safer as well.