Apple's guidelines for App developers are strict, as we have detailed in multiple stories on Game Politics. But as this editorial on Gamasutra points out, the company is also vague in its guidelines - and apparently playing the part of parents who are just too lazy to set up parental controls.
The main thrust of the editorial is about the murky language of Apple's App Store Review Guidelines document, and how difficult it is to get an App on an Apple device given all of these loosely defined restrictions.
Here is a sample on sexual content (from Apple's App Store Review Guidelines document):
"Explicit descriptions or displays of sexual organs or activities intended to stimulate erotic rather than aesthetic or emotional feelings."
And another on violence:
"Apps involving realistic depictions of weapons in such a way as to encourage illegal or reckless use of such weapons will be rejected."
Read Kyle Orland's commentary on these and other sections of the document at Gamasutra.