It works like this: they’re American soldiers, America is a nation which enables and supports homosexuals, and God, well, hates fags. There’s also a godhatessweden.com, I believe, and a couple others – and many, many parody sites (godhatesfigs.com is a good one).
Westboro Baptist Church is comprised almost entirely of Fred Phelps’ family, though a few of his children have managed to break off from it (leading to condemnations and claims they’re damned from the church). I read a long biographical article on Phelps a while back; the man is a dangerous, abusive lunatic. If a tenth of the things in that article are true, he should’ve been locked up long ago.
It isn’t just soldiers’ funerals they protest; they also showed up at Matthew Shepard’s funeral, and have a counter on their webpage reading off the number of days he’s been in hell. They were planning to picket the funerals for those Amish kids who were killed at school a while back, but I believe they called that one off. Right now they’re saying they’ll be at the funerals of the victims of the Virginia Tech shootings.