Both (custom and recaptcha) are essentially security by obscurity, in the sense that a skilled attacker will eventually bypass it. The problem is not that diffi

Both (custom and recaptcha) are essentially security by obscurity, in the sense that a skilled attacker will eventually bypass it. The problem is not that difficult. The advantage Google has is being able to move the goalposts, potentially on a daily basis, while you presumably have better things to do. On the other hand, they are a juicier target, so will draw more effort. Ymmv. Google tends to strike a good balance between convenience and irritation.