Do not connect to Wi-Fi, and other tips for hanging out with 20,000 hackers in Las Vegas

Thousands of hackers, cybersecurity experts, federal agents, and others will descend upon Las Vegas next week for what are always interesting conferences - with talks on as varied applications as hacking cars and airline boarding passes.

Two of the largest conferences in the hacking world will be happening - Black Hat USA and Def Con - along with a Darpa competition between autonomous computers right in the middle of both.

More than 20,000 people are likely to attend.

But what should you expect while you're there? Should a new attendee be worried about getting hacked? What talks are a must?

These questions and more were asked of some past attendees. Here's what they told us.