(I used to work in the Search Quality division at Google.) Security by obscurity is a bad analogy here. The problem is that Google's algorithms are not mathema

(I used to work in the Search Quality division at Google.) Security by obscurity is a bad analogy here. The problem is that Google's algorithms are not mathematically perfect, in the sense of cryptography. Instead, they merely statistically tend to find good results. You can't find bugs just by looking at source code. You have to statistically analyze the effects of any proposed changes.