title: PHP voting system with sessions?
body: <p>I've been reading up on stackoverflow about creating voting systems in PHP that minimize abuse/multiple voting from the same user, but I haven't come across the answer to my question.</p>
  
  <p>I've got an application where users don't need to register to vote or "like" an entry. Obviously, I want to minimize abuse and I don't want to limit votes per IP address because some organisations (mine included) use shared IP addresses.</p>
  
  <p>I've never used sessions in a non-authenticated system before, but since this application is centered around entry votes (used for purely entertainment value, but I'd still like to minimize abuse) I was wondering if this approach would work and whether there were any disadvantages such as performance implications, and whether it's even possible to use sessions in this way:</p>
  
  <ul>
  <li>start a session when the website is loaded</li>
  <li>allow one vote per item per session</li>
  </ul>
  
  <p>If this is a bad idea, my alternative options would be to allow a reasonable number of votes per IP address (say 25), or put a time limit between votes from the same IP address.</p>
  
  <p>What do you guys recommend/what do you think would be most annoying for a user? Restarting a browser, waiting 5 minutes between votes or clearing cookies?</p>