Illinois has its quirks.
This one, though, might puzzle some.
For the state's Supreme Court has upheld the conviction of a man who used his cell phone to take photos of himself and his 17-year-old girlfriend having sex.
The age of consent in Illinois is 17, so the sex was legal. However, as CBS Chicago reports it, Marshall Hollins, who was 32 years old at the time, was convicted of child pornography in 2009 for taking the photos.
He was given an eight-year sentence, but his appeal to Illinois' Supreme Court was heard this week, with the court's verdict -- to uphold his conviction -- handed down Thursday.
It is illegal to photograph anyone under 18 involved in any sexual act. This decision was taken in 1984 by Congress, which raised the age from 16 because, as the Illinois Court explained, "There was sometimes confusion about whether a subject was a minor since children enter puberty at different ages."
Writing for the majority in Thursday's ruling, Justice Rita Garman said, "There are rational, reasonable arguments in support of having a higher age threshold for appearance in pornography than for consent to sexual activity."
These reasons revolve around the notion that a 17-year-old is emotionally competent to understand what it is to have sex, but not to fully grasp the potential consequences of being photographed in the act.
Some might imagine this thought process a little odd, given the prevalence of sexting in seemingly every high school in America.
Moreover, different laws seem to offer a very confused idea of the ages at which people are emotionally competent for certain activities.
You can enlist in the army at 17 (with parental permission), but you can't understand the consequences of risque photographs until you're 18. As for understanding what it is to have a Coors Light, well, you have to wait until you're 21 for that.
The majority insisted, though, that despite the fact that there was no evidence that Hollins had ever attempted to publish these photographs in any way, the Digital Age raises the specter of such shots making their way out into the world, and staying there forever.
"Once a picture or video is uploaded to the Internet, it can never be completely erased or eradicated," Garman wrote. "It will always be out there, hanging over the head of the person depicted performing the sexual act."
Police reportedly began investigating only because of a complaint from the girl's mother, who was somehow in possession of photos Hollins had e-mailed to her daughter.
Hollins' case was surely not helped by the fact that he was already a registered sex offender.
However, the dissenting judges felt that the case was very clear. Justice Anne Burke wrote: "There was nothing unlawful about the production of the photographs taken by defendant in this case because the sexual conduct between defendant and (the girl) was entirely legal."
In the end, Hollins is behind bars, with his lawyer pondering whether she should challenge the ruling.
Perhaps a question worth asking, though, is whether the punishment in this case fits the alleged crime.