How many times is this going to happen before these guys learn their lesson?

Social media has been a prevalent part of the sporting world for nearly a decade now and yet it seems that despite all the missteps and careless opining by mega-stars and prominent sport figures over the years, today's generation of athletes still doesn't get it.

Whether it's commenting on current events, dropping an inadvertent racial slur or just saying something flat out stupid, certain athletes have never learned the lesson and find themselves in a hole 140 characters deep. Twitter is a dangerous place for the average person, so imagine the ramifications that come from a poorly crafted Tweet sent out by an athlete with hundreds of thousands of people (if not millions).

The outcry from fans is far from the problem. A lot of athletes have to worry about their partnerships, whether it's with their teams, sponsors, or anyone closely associated to them. A dumb Tweet can not only make an athlete look like a fool - it can blow up their entire operation. An athlete can lose a lot more than the respect of society when it comes to these kinds of things, the most notable and obvious one being money.

Despite the training sessions from PR departments, specialized communications firms running athlete's accounts, or general awareness to the dangers of social media, athletes have still not learned, and based on history - they likely never will.

Over the years they've tried to hide behind hackers or cover up the mistake by deleting Tweets as quickly as possible - usually to no avail. Once the Internet gets the hold of something, it belongs to the Internet. And it never forgets.

15 15. Johnny Manziel

You knew Johnny Football was going to land on a list like this at some point. Manziel has been (and still is) one of the most polarizing figures in sport for the past few years and it doesn't help when he sends out Tweets slamming his school, Texas A&M, in the middle of the football season. He quickly deleted the Tweet, but the damage was done, and ultimately all he ended up doing was cranking up the heat coming from the spotlight that is always trained directly on him.

14 14. Troy Aikman

Not only did Troy Aikman slip up, he proved himself to be a technological newbie, which is bad in it's own right. A failed attempt at a direct message resulted in a publicly available Tweet clearly showing Aikman attempting to "slide into her DMs". Aikman's slip up is not only embarrassing for him, but it probably ruined any chance he had with the woman he was trying to get in contact with.

13 13. DeSean Jackson

Not only was this DeSean Jackson Tweet dumb, it was quite possibly the laziest Tweet of all time. It's one thing to copy and paste the wrong thing into a Tweet (or anywhere, for that matter) - its another thing entirely to copy paste the instructions. Jackson was either oblivious to what he was doing or is simply a fool. The worst part is that it's blatantly obvious that he screwed up and just makes him look downright stupid.

12 12. Dion Lewis

One of the biggest issues athletes have is keeping their mouths shut when the situation calls for silence. There's no sense in throwing your two cents in on an issue as big as the Aaron Hernandez story, but Lewis decided to do just that. Not only did he Tweet about the case, he Tweeted something dumb. Keeping his opinion to himself, or sharing it with his friends, would have been fine, but calling out a snitch over social media while ignoring the fact that a fellow football player is a murderer seems ill-advised. The Patriots, in typical New England fashion, have seemingly let that slide, as Lewis now features prominently in their offense.

11 11. Davone Bess

Davone Bess' story is more of a sad one than anything else. His struggles with addiction and drugs were well-documented throughout his NFL career, but at times it was his own foolishness that got him in trouble.

In general, it wouldn't seem wise to post a picture of marijuana on your Twitter account - now add the fact that you're already in the NFL's cross-hairs when it comes to drug use, and you have thousands of followers who can get a hold of that picture even if you deleted it within ten seconds of posting it. Bess wasn't quick enough and the Internet got a hold of his "chill night off."

10 10. Carmelo Anthony

Carmelo Anthony has a huge following on social media and for good reason - he's a good follow and he's a terrific basketball player. It would appear that even Melo hasn't been able to restrain himself online, though, as he put a full-blown bounty on a groupie who had pissed him off. That resulted in a police report and a PR nightmare for the Knicks star - one would hope that Melo learned his lesson and won't be dropping pics of thousands of dollars on social media anymore, especially if the money is being put aside to reward someone for slapping a woman.

9 9. Stephanie Rice

Remember when we talked about being careful about what you Tweet if you're a famous athlete just in case you piss people off? Yeah, Stephanie Rice missed that class. What makes that even worse? The fact that she pissed off people that were giving her free stuff. After Australia won a big rugby match, Rice sent out a celebratory but derogatory Tweet (saying: Suck on that f*****s), which promptly resulted in the Olympic gold medalist losing her loaner Jaguar and probably a lot more than the (likely) sweet set of wheels.

8 8. LeSean McCoy

It's one thing for athletes to flaunt their fame and riches. Indirectly, they do it all the time, whether its through flashy Instagram photos or any general association with other famous and rich individuals. It's another thing entirely to establish one's wealth and status by ripping on an ex by calling her out as worthless, dirty and broke over social media for hundreds of thousands to see. You might say that was pretty shady (pun fully intended).

7 7. Damian Lillard

Damian Lillard has developed into one of the best players in the NBA, but before he was tearing apart opponents on the court, he was tearing apart his future counterparts on social media - specifically LeBron James. Lillard went off on James after a playoff series that James' Heat lost in 2011. He expressed regret later on, as the Tweets resurfaced years later and put Lillard in the incredibly awkward position of explaining his rationale for the rant well after the fact.

6 6. Jabar Gaffney

Jabar Gaffney has a history of saying stupid stuff over the Internet. There were more than one ill-advised Tweets over the years, but the worst came when a Cowboys fan chirped the Redskins wide receiver online. Gaffney not only replied, he did so rather harshly, telling the fan that he should kill himself since the Cowboys record wasn't much better. Gaffney tried to justify the Tweet later on, but to no avail - there's no coming back from that.

5 5. Tyler Seguin

There were a ton of reasons why Tyler Seguin was shipped out of Boston despite the fact that he showed a boatload of promise at such a young age. Seguin, who ended up in Dallas (where he has flourished into a star player), gave us another glimpse at what pushed the Bruins to the edge, after sending out a derogatory Tweet upon his arrival in Texas. That might have scared the Stars off and could have set off some serious buyer's remorse, but the situation blew over - still a horrible move by Seguin, though.

4 4. Michael Beasley

The dreaded "what is that in background" picture. It's probably happened to everyone. It's probably worse than simply Tweeting out something stupid, because it shows a general lack of awareness that adds a completely separate layer to these kinds of things. Michael Beasley fell into that trap, posting a picture of a new tattoo but forgetting a small detail in the picture that could (and would) ultimately land him in some hot water.

3 3. Mike Wallace

Not only is Twitter the first place people go to for news and immediate reaction, it's where people go to get a gauge on a population or society's opinion on a matter. Obviously there will be differing views, but one thing that is usually not tolerated is slander and shaming of other races, genders, and sexual orientations. Mike Wallace seemed to forget about that when he Tweeted his opinion on Jason Collins coming out, and he paid for it with some of the harshest backlash an athlete has ever received on social media.

2 2. Cardale Jones

Cardale Jones is never going to live his school Tweet down. No matter how well the rest of his Ohio State career goes, no matter how successful he ends up being in the NFL, this 140 character mistake will haunt him forever. The worst part is that the messaging in the Tweet actually suggests he could use some time in class - maybe someone could teach him how to be a responsible social media user, or a more aware individual in general.

1 1. Rashard Mendenhall 

Rashard Mendenhall takes the cake for simply touching on the wrong aspect of a topic at the wrong time. It's bad enough to start Tweeting about 9/11 (and doing so in a negative light). It's another thing entirely to shoot down a country celebrating what was essentially "justice" for the attacks on New York in 2001, attacks that nearly tore a nation apart, and definitely ruined countless lives. Mendenhall, whether he meant to or not, comes off as defending the deceased Osama Bin Laden, while also questioning the events of 9/11 at perhaps the worst possible time anyone could have done so.

Suffice to say that Tweet didn't stay online for very long.