How to remove commenters ability to add hyperlinks to comments?

I’d like to be able to filter out a commenters ability to add hyperlinks in their comment text.

I removed the “websites” field from the mix to reduce the amount of spammage already (see: Removing the “Website” Field from Comments and Replies?”) which has helped a lot.

By default, they can use the ‘< a ‘> tag to do so in the comment box text, which allows spammers to embed hyperlinks to their sites.

Is there a way to filter out that capability in the wysiwyg editor for comment fields?

WP runs so many prettifying filters on this stuff that it’s easy to get lost.

Here is what I ended up with:

remove_filter('comment_text', 'make_clickable', 9);
add_filter('pre_comment_content', 'strip_comment_links');

function strip_comment_links($content) {

    global $allowedtags;

    $tags = $allowedtags;
    unset($tags['a']);
    $content = addslashes(wp_kses(stripslashes($content), $tags));

    return $content;
}

This scrubs out clearly defined links and removes filter that turns plain text links into properly tagged ones.