If I have 5 candidates who all have the relevant skills, useful work experience, a strong track record, cultural fit, etc, then I might be willing to differentiate them by test score. If one of them scored 1600 on his SATs and the others were 1200-1300, sure, I'll take the perfect guy. They're probably all qualified anyways, no harm in taking the one who's more qualified.
But I absolutely would not institute a minimum test score and only accept applicants above that level. Because too many of the best programmers I know had SAT scores in the 1200-1400 level, and too many folks with perfect SAT scores turn out to be terrible workers. I wouldn't be selecting for anything relevant to my business, I'd just chop out many candidates who might've been a good choice.
If you want to narrow the pool, include a programming problem with the application. Throw out everything that doesn't compile, run, or give the correct answer - that'll cut out most of the chaff right there. Look through the solutions and only invite the people whose code is clean and elegant for an interview. That'll give you far more relevant results. Plus, the very fact that you have an interesting programming challenge tends to attract top developers. One of the defining characteristics of a top developer is that they like challenge.
Hell, you could even make it a part of the application form and check the results automatically. No manual intervention required.
With a hot job market and hiring from (I presume) a no-name startup, you'll be lucky to get 300 hires to sift through. Even more important, those test eliminate some high quality performers. Facebook has a management staff already, and enough money that this is less of a concern.
You on the other hand, would do well to keep every door open. You can't afford to miss that diamond in the rough.