A leak, not to be confused with Link, is when people have problems with their water pipes.
People think some leaks are real because they're polite or know everything about the game or are just a sheet of characters, but most people know otherwise.
The Great Gematsu Leak of '014 was when a huge pipe right below America burst open, causing America to leak through it. It was assumed that She-Hulk was responsible. The pollution leaked into the ocean where many Pale Tunas were killed. America was destroyed, as the Chorus Men sang their last song. Since no one liked America anyway, everyone else says that the leak is a coincidence, but some people think that it's actually a conspiracy by Soviet Russia meant to take America out of the picture. People are using Google Chrom to research, looking at several co-ordinates like X and Y.
A huge leak started in the ESRB, flooding out all of their technology and photographs.
The Tower of Smash (Leak) Edit
It was revealed that Sakurai, prior to his death, was actually working in a tower on making an ultimate weapon to take over the world with Smash Bros. Fortunately, a leak prevented that, and the entire tower sunk and became the Leaning Tower of Pisa.
It first started when the Amiibo were added in Nintendo's CPSIA website thingy there are 4 Amiibo added, all related to smash bros (Bayo was the first to be announced, and Cloud has not been announced yet), many believed that the 4th amiibo was a new character, others stated that it may be a alternate costume like r.o.b's Famicom color Amiibo...
...But when Fire emblem echoes started to leak early, hackers has found files from a female Corrin Amiibo and she was hacked into the game, this was too salty for the smash bros fans and they went angry about this replaced bayonetta's bayonetta 1 costume amiibo, they later revealed that there will be amiibo of alternate costumes for the last three dlc characters, the 4th one is unknown as of now.