In the case of Weaver, et al. v. Harpster, et al., the plaintiff alleged that she was forced to leave her job at a small office because of unwanted (and rejected) sexual advances. She filed suit and alleged violations of the Pennsylvania Human Relations Act or the common law.

The Supreme Court dismissed the lawsuit. It held that companies with less than four employees are not subject to the Pennsylvania Human Relations Act (which prohibits sexual discrimination).

http://www.pacourts.us/OpPosting/Supreme/out/J-53-2008mo.pdf