Question begging, basically. The contention is that they were railroaded and maliciously overprosecuted, it's hard for the answer to be "enough to convince a jury of their peers."
99% of people on this forum (and elsewhere) understand neither the phrase "begging the question" nor the logical fallacy (petitio principii). And thus people are imprisoned. It's sad but this is where we are (and probably always have been).