Even though the phone is being sold as a version of the Android flagship model that can handle anything you throw at it, the warranty states that liquid damage is not covered. That is a bit ironic considering how AT&T's ad for the phone shows it in situations that would certainly destroy a regular Galaxy S4, including scenes showing the phone getting wet. Check out the ad below. The IP67 certification means that the Samsung Galaxy S4 Active can be submerged in 3 feet of water for 30 minutes and be perfectly fine.
The exchange is being offered only to those who bought their unit from AT&T whether it was purchased online or at an AT&T store. The program has started and will run through October or when replacement units are all gone, whichever comes first.
source: electronista, YouTube