There are a lot of collectible items in this world, but nothing like collecting and item that may be worth a lot in a couple of years down the line, or maybe by the time you retire.
American Philatelic Foundation
Once the government found out about the stamps a year later, it was really too late to be able to do anything, although they have issued statements saying that these stamps are stolen property and must be returned to them has done little or nothing by who ever bought the stamps. As some where returned to the US Government many are still with private collectors that cannot openly display the, or sell them.
The stamps are now said to be worth around$10,000 - $15,000 dollars, the Value may increase because of how rare an error like this is seen, as well as how they are considered stolen property and therefore taboo to sell or display.
If you have collected stamps or own some and would like to get the appraise, please visit American Philatelic Foundation