If you look at the pictures in the article, you'll first see the counter-protest (very clever, by the way, and I would have loved to participate, so you can see which side I land on here). But just a little ways down, you can see some of the signs the church members hold.
God hates America
You're going to Hell
You hate God
God is your enemy
And my personal favorite: God hates you
Not only do I believe these are completely unbiblical statements, I also don't see how they are helpful in any sense of the word. Even if they were all true, how does making glaring signs of these statements make ANY change?
Many of us do have signs, bumper stickers, license plate frames, posters, etc. with more accepted sayings, often with the hope of changing someone's life or bringing them to Christ.
When was the last time you were transformed by a sign?