Camping out is a cracking technique that involves waiting for a vulnerability to come along so that it can be exploited by the cracker. For example, a cracker can scan all the equipment and services exposed to the Internet, and, for example, record all the banners and then look for vulnerabilities. The cracker then camps out, waiting for a Zero-day exploit to be posted to various places—at which point he or she launches the attack against the target and gets entry into the system before the hole can be patched.
Graham, R. Hacking Lexicon. [Online, 2001.] Robert Graham Website. http://www.linuxsecurity.com/resource_files/documentation/hacking-dict.html.