Yeah, I was wondering about that myself. I would hate to start seeing whales wash up on shore with a big latex balloon stuck in its throat. <img src="/images/graemlins/shocked.gif" alt="" />

The article only mentions that the balloons eventually burst from internal pressure once they float high enough. I assume that the remains will land somewhere, like someone's front lawn, rather than disintergrate somehow on the way down. There's no bounty on the balloon, so you'll have to dispose of it yourself if it lands on your property.