Is hosting on the same IP with spam sites bad for your website’s ranking?

A student in last Website Design class asked a similar question to this one:

“If my web host has a lot of spammy clients, will that influence my site’s ranking?”

Basically they were wondering if shared hosting at a company like HostGator is safe and if they are sharing space with spammy sites will it decrease a website’s search engine ranking.  

The short answer is NO, although there are a few RARE exceptions.  Here is Matt Cutt’s (leader of the Webspam Team at Google) answer: 

The reality is most of the Internet’s websites use shared hosting because it is inexpensive and generally provides the same features and functionality that dedicated hosting does. Your biggest concern, when it comes to shared hosting, is up time (for obvious reasons) and site speed which is an important factor impacting your site’s ranking is the load time of your website.  If there are too many other websites on your server that get a lot of traffic it could potentially slow down your website.