Deregulation in the sense of stripping very specific regulations designed to prevent exploitation are typically good for the owners of capital and bad for everyone else. Examples include the Depository Institutions Deregulation and Monetary Control Act (Led to Savings & Loan calamity), the Gramm Leach Bliley Act (Led to GFC), California's attempts to deregulate the energy market (Led to Enron and the energy crisis). It's easy to imagine many more scenarios where industries could be deregulated that would cause massive harm to most of society -- virtually all environmental controls fall into this category.

Some of those scenarios could have been prevented if more facets had been deregulated, but they weren't so we lost trillions of dollars in real value and drove debt through the roof.

http://en.wikipedia.org/wiki/Depository_Institutions_Deregul...

http://en.wikipedia.org/wiki/Gramm-Leach-Bliley_Act

http://en.wikipedia.org/wiki/California_electricity_crisis