acquiring unlisted properties (reo's)

[Stephanie Fay]

Every good REO property I've come across (I use mostly use county clerk, tax collector and property appraiser sites) are not yet listed on the MLS. I find it impossible to believe that I can not make an offer on these properties until they become "available". I read a great article recently,

http://realestate.aol.com/blog/2012/07/13/shadow-reo-as-much-as-90-percent-of-foreclosed-properties-are-h/

about foreclosed properties sitting in limbo.  Is it actually true that a bank would rather sit on a toxic underwater note than get it out of their hair?  I'm pretty new to the scene, so forgive any ignorance.