The facts of this incident remain a bit sketchy, though it remains great news for Incumbent Sen. Jim DeMint. 
Greene, an unemployed veteran who lives with his parents, was a surprise winner in the primary over former four-term state lawmaker Vic Rawl, 64. He was arrested in November and charged with showing obscene Internet photos to a University of South Carolina student. If convicted, he could be sentenced to up to five years in prison.
He has refused to comment on the charges, though he reportedly showed the woman the pictures and wanted to go up to her room. I am quite surprised to see such a matter result in a formal criminal charge, let alone a felony. If the individual is not distributing pornography or making threats, prosecutors usually treat this as creepy or boorish behavior. Obscenity remains an often ambiguous concept in criminal codes. Reports indicate that Camille McCoy, a 19-year-old rising sophomore, said that Greene sat down next to her in a computer lab and asked her to look at his screen which showed a porn site. That is usually not enough for a criminal charge. Moreover, it is hard to imagine that the police could show for sure which image was showing on the screen at the time. There are often complaints of people watching pornography on airplanes or college computer labs. Such conduct can result in expulsion from a public area or even a school, but rarely rises to the level of a criminal charge.
It is not clear how they will prove the specific image shown on the computer, though they can likely show what images will viewed on the given computer during that period. If he did in fact invite the person to look at the images, there is a question of presumed consent. The person had to actively turn to look at the image. This would appear to be the type of case the defense counsel warn their clients about in terms of publicity: one week on the cover of Time, next week doing Time. Publicity in such a matter can draw prosecutors to a case that would be ordinarily dropped. I believe he would have some strong defenses at both trial and, if needed, on appeal to such a charge.
Source: CNN