This is considered ‘mortgage fraud’ and could have serious legal consequences and that’s the last thing you want. Many homeowners may buy and bail and believe that what they are doing is justified because they were misled. For example, a real estate agent may have led the buyer to believe that home's value would never fall. Another possible scenario is that a bank may have told the homeowner that refinancing would be an option that would always be available to them. Then, the bank changed their lending policies and the buyer cannot obtain a new loan.
These are scenarios where a homeowner may feel like they were deceived. Do not make the mistake of doing this, no matter how deceived you may feel, because you may end up going to jail. Buy and bail is considered a mortgage fraud because often the borrower does not reveal certain information such as their intention to discontinue making payments to another creditor. That is the part that is considered fraud. It is punishable by up to 30 years in prison and a fine of up to $1,000,000. Doesn't sound like fun, does it?
If you do want to short sale and buy another house, then make sure you talk to competent legal counsel before trying this or a similar strategy. They will be able to tell exactly what is illegal and what is now illegal. With their guidance you may be able to buy another home and then short sale and do it legally.