Just because you call it a business does not mean that the IRS is required to agree with you. The IRS has authority to presume that an activity can be charecterized as a hobby. As a result, any losses associated with the activity could be disallowed.
Some taxpayers have a hobby or craft that could be a money maker. This could be almost any type of activity whereby you charge a fee or sell a product. The mere fact that you call something a business, does not mean that the IRS cannot disallow losses or expenses related to your business or hobby.