Niners fans are fighting back.After Seattle Seahawks fans scrounged up enough dough to buy a brick at the 49ers' new stadium in Santa Clara, and arranged earlier this month for a pro-Seahawks banner to be flown over Candlestick Park, San Francisco's faithful fans have raised money to purchase a billboard in Seattle.Fans of the 49ers have accumulated more than $9,000 to rent a billboard of their own that taunts Seattle residents with visual reminders of the five Vince Lombardi trophies the 49ers have picked up through the years.MORE: Niners Appear Much Stronger at CornerbackThe online fundraising effort was spearheaded by Aasheesh Shravah, who posted this note thanking contributors: "Thank all of you so much for your generosity and showing the world what team has the best fans!!"Sure, there be might more constructive ways for the money to be spent, but rest assured, all money exceeding the project's estimated $7,000 price tag will be donated to Seattle Children's Hospital.While the back and forth between the fans adds intrigue to the NFC West rivalry, a billboard reminding the Seahawks that they have no Super Bowl championships could give them extra motivation to secure their...