It's a simple logo that represents a married family.
It also represents millions of dollars donated from people and groups outside of California. Homophobic religious groups from across the nation see California as a battleground for biblical values. They want to condemn same-sex marriage as being unholy, but if they do, they'll be seen as bigots and discounted. They'll lose if they state their position clearly.
The list of endorsers looks like a "who's who" of uptight puritanical "I know what's best for you" Christian organizations. (Interesting - many of them are Mormon.)
The logo also represents the lies and misleading half-truths that are being told in the "Yes on 8" commercials. The commercial says that if Proposition 8 fails:
1. Gay marriage will be taught in school.
What does that mean? It means that religious schools that are accredited by the state must teach to state mandated guidelines. So, if same-sex marriage is legal, then it will probably come up in a discussion of marriage law in a student's government classes.
What will also come up in those same classroom discussions is that the anti-miscegenation laws and segregation laws were overturned by the Supreme Court. If the people who support Protectmarriage.com were active in 1953, they'd be just as "concerned" that your child might be forced to be taught in the same classroom with some "colored folk".
I would suggest that if your child is going to a school that doesn't teach the reality of what is happening in the world, then perhaps your child will be unprepared to deal with reality.
2. People can be sued for their personal beliefs.
People can sue people for anything. But I question whether it is worth the trouble. A suit over "belief" will get thrown out. It is how you act on your belief that matters. A guy might believe that it is okay to somehow oppress his neighbor, but unless he acts upon that belief, he isn't guilty and any suit against him would be frivolous.
If you believe that homosexuals "deserve to die" (Rom 1:26-32), well - it's evil, but it is your opinion. But if you use your beliefs to incite murder then you should be sued. (You should be jailed!)
So what you believe is your privilege. How you act is society's concern.
3. Churches will could lose tax-exempt status.
I'll tell you now that if you are politicking from the pulpit, then you are breaking the law. Some preachers don't see the problem with threatening their congregation with damnation for not voting as directed. This is wrong, and it is illegal. If you don't like it you have two choices. Either stop with the politics, or work to change the law.
But here's some good news for you. If you want to preach that same sex marriage is wrong, that it is against the word of God in the Bible - you are welcome to do so! If you want to forbid your congregation from going to a same sex marriage, or withhold communion from people who attended a same sex marriage that is your right to do so.
And any church that refuses to marry a same-sex couple gets a free pass! If your church doesn't want to participate in a LGBT marriage, then no one can force you to do so.
And that's fine too. There are plenty of other churches that WILL marry same sex couples. Maybe your sister church is willing to perform a LGBT marriage. Maybe you're IN a church that is accepting. Maybe this is what is really bugging you. Maybe it is time for you to change to a different congregation. I hear that Stormfront is anti-LGBT and is looking for new members.
Here is the "Vote No on Prop 8" commercial that counters these lies.