One of the cutest cartoon bears of all time, Pedobear was an ASCII image on the Japanese image board 2Channel, where it was mostly a symbol of people trolling each other. Whenever people in that community would screw with each other, Pedobear would be an almost "nyah nyah" type figure that represented the fact that someone had been "trolled", much like the currently used trollface.
But when it came to the states to the popular image board 4Chan (the 1,007th most popular website in the world), people started using it along with Loli hentai (animated Japanese pornography starring underaged cartoon characters -- you're welcome). Thus, Pedobear as a pedophile was born (hence the "pedo"). And since then, even though it is occasionally used by 4Chan's /b/ to identify threads where people are uploading illegal content (which is promptly taken down according to this Reddit AMA with one of the enigmatic mods of 4Chan), it has become a horribly, despicably inappropriate joke that people are just really having fun with.
It's the internet, and no matter what the horrible, terribly timely, most disgusting thing on earth might be at the moment, there will be jokes. And in this case, it just happens to be pedophilia. And it's a really "wrong" joke, but it's generally harmless.
After the "Pedobear Seal of Approval" stopped being his main thing, people just started putting him on images and generally everywhere on the internet.
Pedobear Image manipulations:
Pedobear Image Macros
And people even dress up as Pedobear at places like San Diego Comic-Con (as a joke):
So, unlike the news report says, next time you see a Pedobear sticker, insignia, street art or someone dressed as Pedobear, it's not a sign of people nearby raping your children in an empty storage units, it means people are spreading an internet joke.
U MAD BRO?
"You mad bro" is based in the art of disrespect, originating in freestyle disrespect battles of the hip hop music scene. The phrase "You mad" typically preceding reasons why the rapper is better than his rival. The meme was picked up after an episode of The O'Reilly Factor in 2003 that included an interview with rapper Cam'ron and his producer Damon Dash. During the interview, Cam'ron (off screen) says "You mad" to Bill, after Bill continuously cuts Damon Dash off and talks over him. Shortly thereafter, the first "You Mad (Bro)" image appeared on online forums, with Cam'ron laughing and pointing to the left.
The meme has evolved from an aggressive attack to either a taunt or another way of saying "calm down", depending on context; though both are rooted in claiming one's superiority. Typically it is just "you mad", "you mad, bro" or "u mad" text over a picture. There may be additional text which an explanation of why a person might be mad. This is one of the most diverse memes as it can be used for any situation based in controversy and it also easily crossovers with other memes. A football game seems like an easy place to find the meme, with the victors proudly proclaiming their triumph.
Here are some examples:
This, as many memes, was brought into this world thanks to Anonymous. Banding together, a group of 4chan users hopped onto the virtual game Habbo's Hotel and began blocking off various sections of the game to its users, such as (you guessed it) the pool. The image used is based on the avatar skin each member used.
The ironic thing about this particular meme is that it was created because it was believed that the moderators of Habbo's Hotel were abusing their powers against black-skinned avatar users. The movement was created to cause blockades and disrupt game play. Using a black avatar, with a suit and afro, Anonymous wanted the avatar to represent a rich black man. Eventually the movement spread to other forums and sites, like Encyclopedia Dramatic and YTMND. As a result, people began to print off images of the meme and posting them on real life pools, leading to ridiculous stories such as these to be in the news.
In Habbo Hotel:
We've all experienced this at least once. Someone you trust links you to a YouTube video, a bit link, or some other kind link where you can't exactly discern where the path might take you. Nevertheless, you foolishly venture onward only to learn that you have been duped into watching and listening a Rick Astley video. Congratulations, you have successfully been rickrolled.
Beginning in 2007, 4chan gave us this little nugget, on the videogame forum /v/, where one user claimed the link led to a much desired GTA IV trailer. As it was a highly anticipated video, many fell prey to the original poster's bait-and-switch tactics and so it all began. Rick Rolling has since become a common prank, even used by Google as a joke on April Fool's Day. The coup d'etat however was in November of 2008 when Rick Astley was brought out as a surprised guest on one of the floats during Macy's Thanksgiving day parade.
The newsworthy story comes about 7 months early, in April of 2008, when the Mets were looking for a song for their 8th inning sing-a-long. And so the internet hoards came and voted like mad for the song; leading to boos and cries of displeasure from the crowd. The reporters then tracked down one of the producer of the song to get his opinion and, of course, rather than seeing it for the joke that brings tears to children, he sees it as Rick Astley once again "capturing the imagination" of the people and has always been an amazing song that people loved. Clearly, he didn't get the memo.
(Coincidentally, Rick 'gets' it and said that MTV was successfully "rickrolled" when he was nominated for Best Act of 2008).
Though it is mostly a video gag, there are also picture versions of the meme.
And, of course, here's the original video for any under-rock dwellers...