You're probably far from the only one having such thoughts given the recent disastrous overspeculation-collapse cycle.
I haven't lost a home to repossession myself but I can understand feeling like you want to go back; sometimes I drive by my old house in Arlington County and wish I could walk through it again.
That said, you don't want to get stuck with charges for trespassing or breaking and entering. The radio code has probably been changed so I doubt you’d be able to get in without picking a lock or climbing through a window etc. People might be watching and might report you to the police, depending on what the neighborhood’s like and whether or not you can conceal yourself while trying to enter. If you do go I wouldn’t recommend staying there for more than a few hours, and would say you shouldn’t bring a lot of stuff in or use the utilities (though I’d think they’d be suspended if it’s empty) since more time and activity makes it more likely you’ll be discovered.
This is somewhat tangential and more of a policy consideration that your post just happened to remind me of but:
One thing I've thought about frequently since the housing market started to tank over two years ago, is whether high foreclosure rates have produced a glut of unoccupied housing.
Because to the extent that it has, it would seem that it should be used to temporarily shelter those who would otherwise have no recourse but overcrowded public or charitable shelter facilities, which can eventually reach their maximum safe capacity and be forced to turn people away in particularly bad times like these.
A few months ago I read this article about an unemployed software engineer who slept four nights in Golden Gate Park because there was only enough room at a local shelter for his wife and kids:
http://www.dailyfinance.com/story/co...cisc/19290233/
Of course, there are logistical and security problems with such a plan to supplement housing for those who can't even afford to rent cheap quarters. There's a portion of homeless who are reliable workers (in some cases even highly skilled) and have relatively good credit histories (aside from possibly recent foreclosure and/or bankruptcy caused by having entered an adjustable-rate mortgage for which it should not have been legal to approve them in the first place).
But there's also a portion that is to varying degrees unskilled, untrustworthy, irresponsible, mentally ill (I don't mean to associate any stigma with the term; I just mean that it makes you a higher risk for a lender since you're less likely to have a high and stable income), has substance abuse problems, or whose livelihood depends on criminal activity like dealing drugs, identity theft, gang involvement, etc.
Because currently unoccupied properties that could theoretically house the homeless are often not clustered very close together, it could be exceedingly difficult for municipal housing authorities and police to check up on the residents to see if they are pursuing employment and/or education / training programs, whether the properties are overcrowded, whether they're being used for illegal purposes like housing meth labs, or being sublet to others at mercenary rates by dishonest occupants.
It seems that a failure to prevent occupants from making choices that are unwise in the long term, could result in costly damage to the structures and more importantly, to these people and their dependents. However, I’m sure a lot of aforementioned damage to people is already being done when they’re homeless, or living in packed shelters with others who compound their problems. So yeah, it’s a tough issue.