I run a couple of short URL websites and this kind of short URLs along with links to phishing and spam sites is what you&#x27;ll get on a very regular basis in this business.<p>Those short URLs are often being used in mass mailings, guestbooks, comment forms etc. and they&#x27;ll get reported pretty quickly to URL blacklists. That gives you the chance to disable the shady short URls before too many people come across them.<p>Here is a list of URL blacklist providers that you should check each URL against, both before accepting it into your database and again before you deliver it to the user:<p>multi.surbl.org, 
uribl.swinog.ch, 
dbl.spamhaus.org, 
url.rbl.jp, 
uribl.spameatingmonkey.net, 
iadb.isipp.com, 
dnsbl.sorbs.net<p>You can find out more about this stuff on <a href="http:&#x2F;&#x2F;www.surbl.org&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.surbl.org&#x2F;</a><p>Since I&#x27;ve implemented these checks I only receive complaint emails every other month and no contact from the authorities so far (in contrast to the disposable email services I run).<p>When you get a complaint about a URL, your software should allow you to disable all the URLs of the reported domain. There are times when the spammers have taken over a forum (or any site really) and created a large amount of spammy content.<p>Hope this helps.