Given the task definition and input, reply with output. Write an inquisitive question about a specific text span in a given sentence such that the answer is not in the text.

Sentence: Public confusion , legal loopholes and shady Internet businesses have led to an " epidemic " of fake service - dog certificates , vests and harnesses for use on ordinary pets .<sep>Span: legal loopholes
What are the legal loopholes that have led to the 'epidemic' of fake service dog certificates?