Exactly. The vast majority of captcha usage is completely unnecessary. Just remove it. As you say I've even seen captchas for static content, which is pure nons

Exactly. The vast majority of captcha usage is completely unnecessary. Just remove it. As you say I've even seen captchas for static content, which is pure nonsense. I run several long-lived (decades) sites with mostly static content but also some dynamic pages and a commenting mechanism. Here's what I do to prevent abuse: nothing. It's fine. If you run a massively popular site or something politically controversial then you'll be targeted for abuse. If you're specifically targeted, I don't know how much captchas will help. For the rest of the 99.9% of sites, just stop it. You don't need it.