PHP: Function to Strip URLS from Text

Prevent users from posting unwanted URL, and protect yourself from malicious posts or in appropriate urls being posted in your content.

function removeURLs($haystack) {

// unwanted tags separated by vertical bar
$strip_tags = "a|script|p|font|style";

$haystack = preg_replace("#<\s*\/?(".$strip_tags.")\s*[^>]*?>#im", '', $haystack);

// http(s)://
$haystack = preg_replace('|https?://www\.[-a-zA-Z\.0-9]+|i', '', $haystack);

// only www.
$haystack = preg_replace('|www\.[-a-zA-Z\.0-9]+|i', '', $haystack);

// Back Up
$haystack = preg_replace('/\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|$!:,.;]*[A-Z0-9+&@#\/%=~_|$]/i', '', $haystack);

$haystack = str_replace('<a href="', "", $haystack);
$haystack = str_replace('">', "", $haystack);
$haystack = str_replace('</a>', "", $haystack);

return $haystack;

}