ANSWER: URL shortening websites such at bit.ly. The normal technique anti-spammer solution to detect bad URLs is based on DNS lookups on the domain portion of the URL. So, a spammer using bit.ly/897237 and a good URL of bit.ly/329082 were considered equal. So, the new anti-spammer technique to address this to use the full URL. So, make sure you’re anti-spam solution is capable of checking full URLs. The anti-spammer technique for URL checking is called SURBLs. Make sure your SURBL solution can look-up full URLs. such as this bit.ly/searchthispart.html as well.