What's most interesting about this is how little esoteric tech there is in catching underground desaparecidos -- tap a phone or two, look in their Google caches, wait for them to use their SSN or register their kids at school (how Ratliff Sheppard got caught). The database nation turns out to be a most banal panopticon.
Two weeks before, when Sheppard sat down to formulate a plan to fake his death, he'd been armed only with Google and LexisNexis. Stumbling on an article about Steve Fossett, the explorer whose plane disappeared in September 2007 and whose remains were yet to be discovered, Sheppard concluded that even without a body, Monica would likely be able to obtain a legal determination of death and thereby collect his company-issued life insurance policy -- worth $1.3 million. He pored over recent reports of missing persons and faked deaths, looking for strategies to emulate and pitfalls to avoid.Gone Forever: What Does It Take to Really Disappear?That, in fact, was how he'd come up with the idea of leaving his BlackBerry conspicuously at a gas station on the Friday before his disappearance. It was a classic misdirection: Someone would grab the phone and start using it, Sheppard hoped, and any cop who didn't buy the drowning would trace the phone to some petty thief -- while Sheppard's real trail faded. (The ruse backfired, it seems, when the thief sent a few messages and then quit, convincing Sergeant Roberson that Sheppard was alive.)

"how Ratliff got caught" should be "how Sheppard got caught". The article's author, Evan Ratliff, has also disappeared, but as a magazine contest, and he hasn't yet been located.
The moral of the story is that even the most inept police can stumble upon you if you make enough mistakes. God help you if you are actually trying to be found.
Osama, where art thou? And D.B. Cooper is where?
It would have been easier for him just to stay where he was and deal with his issues.
what does it take to really disappear? Lose all your money and property publicly. Poor people are invisible.
Repeat after me: "Blank is beautiful! Blank is beautiful! Blank is beautiful!"
I think what we'll have to do is "SeaStead". Really quick start building living platforms and also underwater habitats. Work with island nations that are "Shrinking". Build them habitats in exchange for them incorporating yours into their nation or getting them recognized by the U.N. That would stop the US and other nations from openly attacking and give us time to prepare countermeasures for later.
What we'll do is create "Oceana", a confederate of independent nation states with only the laws they choose for themselves. As prices for food and fuel become nightmarish an artificial island complex with garden towers would become quite profitable and sustainable. It's fair: No law to mess with you, but no law to protect you. You work for no one but yourself and perhaps your tribe, but you must work or die.
There might be a problem now if you started one and both grew Marijuana for outside sale and had cute lil brown girls for mistresses and had your "Independent MiKroNation" featured in WIRED and bOING bOING, but in 10 or 20 years the USA will be too busy resisting state secession and armed takeover by gangs and Neo-Nazi/Militant Christian groups and unable/unwilling to mess with you.
_The Flight of the Falcon: The True Story of the Escape and Manhunt for America's Most Wanted Spy_
explains how Christopher Boyce evaded capture for 20 months after escaping from prison (he grew pot and robbed banks).
With a wife and kids it would be impossible.