This sounds like a strange thing to do, but we're talking about reducing bacon shrinkage. The claim is that rinsing your bacon before you cook it will result in longer strips to enjoy.
This tip has been circling around the internet for a while. Fran at the Franalan blog put it to the test and confirmed her bacon did not shrink.
Also, cooking bacon in the oven definitely is a superior method, but if you want to cook it in a skillet, Cooking Light suggests you could also prevent some shrinkage by starting with a cold pan and flipping often.
Ditch the Skillet; Fire Up Your Oven to Cook Perfect Bacon
Correction: A lot of people have put this to more strict testing and found that the rinsing doesn't do much—instead, cooking it in the oven is likely what causes the larger bacon. The takeaway? Cook your bacon in the oven, folks!