One would think. However, the way the courts have begun to interpret the law, mens rea is unconstitutionally not required. Regardless of the due dilligence that may have been exercised, one can and will be convicted if a jury can be convinced that minors were filmed in a sexual context. Parents have been convicted for baby pictures; the children themselves have been convicted for autophotography.
Same problem exists when environmental laws are violated: ignorance and/or good faith errors are not permitted as defenses. In other words, criminal law has begun to be enforced as though it was merely administrative regulations (where mens rea is not required, but also where a civil fine is supposed to be the maximum penalty.)
The Framers didn't put an explicit requirement for mens rea into the Constitution, for two reasons. One is that it was so fundamental to Anglo-Saxon legal principles, they simply assumed it as a bedrock part of common law. But more importantly, they thought they had written a Constitution that severely restricted the authority of the Federal government, and that it was only authorized to criminalize a few things. Thomas Jefferson enumerated them in the Kentucky Resolutions:
... the Constitution of the United States, having delegated to Congress a power to punish treason, counterfeiting the securities and current coin of the United States, piracies, and felonies committed on the high seas, and offenses against the law of nations, and no other crimes whatsoever; and it being true as a general principle, and one of the amendments to the Constitution having also declared, that "the powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people," therefore the act of Congress, passed on the 14th day of July, 1798, and intituled "An Act in addition to the act intituled An Act for the punishment of certain crimes against the United States," as also the act passed by them on the -- day of June, 1798, intituled "An Act to punish frauds committed on the bank of the United States," (and all their other acts which assume to create, define, or punish crimes, other than those so enumerated in the Constitution,) are altogether void, and of no force; and that the power to create, define, and punish such other crimes is reserved, and, of right, appertains solely and exclusively to the respective States, each within its own territory.
He would be a world of hurt if it was proven that any of the models or porn stars on any of his films or website where underage.
The porn industry is very maticulous about this, as they are with aids and STD's tests these days.
While Max's films are nasty, the women in these films are consenting adults and paid for their performances.
Most pron stars are part time prostitutes as well.
While I easily choose not to view Max's stuff because it does nothing for me, I don't like the government getting involved in this, unless, Max did have non-adults involved in his material.