Apologies to AC1997, but my reply turned into a diary. There is a lot of snark here, it's not aimed at you, it's just because I'm snarky.
Brian's mentioned Bill Simmon's article about PEDs and its natural extension into college recruiting. Whenever a school, Ole Miss in this case, gets a recruiting windfall, illicit or otherwise, or has a sustained run of success at the top, like USC, lots of folks question whether or not the success is legitimate. Then, they openly speculate, often using terms like "U$C" or "Ole Mi$$," (AC1997 did not do this) why no one sheds light on the violations. Here's my take as to why really big recruiting violations rarely come to light.
First, let's set the scenario. Phil Philbert is a five star dual-threat QB from Springfield. Instead of staying home to play for Local U (LU), he instead goes to Football University (FU), which is on the other side of the country. LU fans cry foul and demand justice, but no one sheds light on why Phil was seen leaving town in a new Maserati.
In this scenario, I think there are three ways Phil and FU get caught:
Concerned insider tells all.
First, we all know the NCAA isn't out to discover recruiting violations. If the NCAA is a part of a police force, its job is that of a detective. In other words, they here about something bad and investigate to determine what happened and who is responsible. This detective would be taking many of its calls from cops on the beat. The only problem is, there aren't any paid cops on the beat. If the NCAA and its members wanted that, there would be paid staff at FBS schools "patrolling." No one involved really wants that. Therefore, the NCAA is waiting by the phone for options 2 and 3 to call before starting an investigation.
The most obvious person to call the NCAA would be the concerned insider. They would have first-hand knowledge of the situation and could steer the NCAA toward FU's egregious violations. The problem is, who are these insiders with direct knowledge? The parties with direct knowledge are:
Phil's high school coach.
The deep pocketed booster who bought the Maserati.
None of these people has any incentive to talk. Phil and his family got a free car (or cash) and don't want to go to jail for not paying taxes on the gift. Phil's coach can't tattle or he gets fired and his high school becomes persona non grata in recruiting circles. FU's coach doesn't want a show cause penalty or to lose his buyout. The booster and the bagman love FU too much to tell. Anyone else who talks has circumstantial evidence unless Phil (or the bagman) is dumb enough to talk about their nefarious deed into a microphone.
That basically leaves investigative journalism. However, there are serious problems with developing these types of stories. Even disregarding the lack of actual journalists who have the skill and tenacity to run down these types of stories, they still have to get someone to talk. That's really hard. Additionally, which news outlet would run the story? The most obvious one is LU's home paper. However, LU's home paper probably isn't doing very well right now and is likely devoting their investigative stories (if there are any) to things like crime, serious corruption, or serious societal issues. FU's home paper is definitely out. Papers struggle for readers as it is, they don't need to anger their subscriber base by getting FU in a bunch of trouble.
That basically leaves Charles Robinson at Yahoo! and a few other journalists at big-time news organizations who have the time and organizational backing to do this type of work. I heard an interview with Robinson a year or two ago. In it, he basically said he has a bunch of Nevin Shapiro / Miami stories in the works at any time, but journalistic standards of prohibit him from publishing until he can get credible on-the-record conversations and / or a lot of verifiable evidence. Again, that's really hard to come by given the few people with insider knowledge and their lack of incentive to talk.
This is one guy's opinion as to why serious recruiting violations don't come to light very often. They're hard to find and hard to verify. Furthermore, I don't believe much really serious stuff actually happens anymore. It's too easy for someone to Tweet a picture of himself holding a stack of cash and add "loving FU right now, LOL." Cheating today is an incredibly short-sighted tactic that can't go on long. It would be impossible for wholesale, SMU-style cheating, to be kept quiet, just like it was then.