http://www.playxp.com/sc2/tip/view.php?article_id=3350319
A Korean Protoss pro MilkyWay has just released a method to completely stop apylon/bunker wall in at the opponent's ramp between the base and the natural.
I personally believe that artificial controls over game plays must be minimized, so I'm creating a new thread to inform this tip, encouraging foreign tourneys that use neutral supply depot to prevent wall in rush to remove those depots from the map, since the particular play can be overcome with the tip Milkyway provided.
The tip is very simple. When your ramp is blocked by your opponent, you first gather your workers near by the ramp. Then you should click on a mineral patch in your natural. The workers will stack right in front of the wall. Modedit: You must have vision of the mineral patch in order for your workers to stay stacked, if not you'll have to spam right click on the patch to keep em stacked, or they'll fan out. You should A-click the wall, which will instantly cause your slack to go loose. You should quickly re-click the mineral patch, and keep doing this until the wall is broken.
According to Milkyway, this method will deal a damage of 50~60(depending on your neat execution and worker counts) per attack and you will most likely break through the wall when the first cannon is about 50% done. You should force cancel the cannon/ other bunkers under construction using your workers.
Milkyway added in comments that Protoss will virtually have 0% winrate if their cannon rush fails this way, since Zerg would suffer almost 0 damage(little mining time), while Protoss would lose 3 pylons and a few cannons. He even recommends Zerg players to induce Protoss to do cannon rush if the zerg player is confident with his execution of this Wall Breaker method. He asserts that this will 100% prevent/stop cannon and bunker walling in rush, if executed properly by the defender. He also said that Zergs should always take expansions first to maximize the advantage.
I never liked foreign tourneys preventing wall in type rushes by artificial means because you actually can prevent it with pure micro skills such as by putting your worker on patrol and using your workers to repel your opponent's probes/scvs/marines. It just required some attention and fair micro.
Anyways, since the hard counter has been released, I hope we do not see neutral supply depots to prevent wall ins on foreign tourney maps anymore.
This is my first thread, so I hope I didn't mess up anything big. Rejoice, Zerg players.
Milkyway's original post was blinded because angry Protoss mobs thumbed down this tip(it was more like prank thumb downs because Protoss is doing so poorly in Korea. With today's result, Protoss's winrate in current GSL dropped to 31%. I'm mentioning this to explain why Milkyway's great thread was blinded, so please stay refrained from off topic balance posts.)

Edit: I am not the original finder of this method, so feel free to post this method in any other boards you see fit as the mod suggested. I, as a newb to TL, am not really familiar with the purpose of each board. I also edited out a word "close" from the description of which mineral patch you have to click. Thanks for pointing it out for me!