I created a portal in the nether and it led into an abandoned mine. I explored the abandoned mine for a while before re-entering the Nether where I found a number of skeletons and zombies had wandered in. One of the zombies attacked me, so I attacked back and I think the surrounding zombie pigmen became hostile (I died before I knew what was going on).

Can someone confirm that this actually does happen? Is this a bug or is it intentional? (ie the zombie pigmen see their overworld counterparts as kindred spirits or something)

I was on snapshot 14w06b