Conspiracy theories are often portrayed as unwarranted beliefs, typically supported by suspicious kinds of evidence. Yet contemporary work in Philosophy argues provisional belief in conspiracy theories is at the very least understandable---because conspiracies occur---and that if we take an evidential approach, judging individual conspiracy theories on their particular merits, belief in such theories turns out to be warranted in a range of cases.
Drawing on this work, I examine the kinds of evidence typically associated with conspiracy theories, and show how the so-called evidential problems with conspiracy theories are also problems for the kinds of evidence put forward in support of other theories. As such, if there is a problem with the conspiracy theorist's use of evidence, it is one of principle: is the principle which guides the conspiracy theorist's use of evidence somehow in error? I argue that whatever we might think about conspiracy theories generally, there is no prima facie case for a scepticism of conspiracy theories based purely on their use of evidence.