Question: Some days ago, the spam protection was turned up a notch.

Unfortunately, it overshot the target by far. Now, as soon as I make two edits in close succession (which happens *often* – I’m sloppy), I am presented with a “human verification” and a **totally unreadable captcha.** It takes an average of five reloads to get a marginally readable one, and even then I’m guessing (and sometimes guessing wrong).

Please tune down the filter, or at least switch to a readable captcha.

In fact, wasn’t there previously a rule that once contributors had enough reputation, they’d be trusted not to be bots? Did that get switched off or am I remembering this wrong?

Answer: 
> 
> Some days ago, the spam protection was turned up a notch.
> 
> 
> 

[Well, actually](http://tirania.org/blog/archive/2011/Feb-17.html), it was *repaired*. Two weeks ago, we found a bug that for a long time prevented edits from being throttled *at all* (except for very narrow exceptions).

For the record, I posted this in our internal chat room:

![prescient chat message](https://i.stack.imgur.com/f8DXG.png)

Thanks for proving me right :)

In all seriousness: The throttling was fixed to do what it was supposed to do all along, and not technically turned up a notch. I'm well aware that this doesn't really make a difference to the user; I'm just explaining what was going on.

> 
> and a **totally unreadable captcha.**
> 
> 
> 

Yes, this is a problem. Both [Meta](https://meta.stackoverflow.com/search?q=recaptcha+hard+difficult) and the [general internet](http://www.google.com/search?q=recaptcha+hard+difficult+unreadable&tbs=qdr:y) are overflowing with complaints that many reCAPTCHAs have become close to unsolvable recently. This is something we have to tackle one way the other.

> 
> In fact, wasn’t there previously a rule that once contributors had enough reputation, they’d be trusted not to be bots? Did that get switched off or am I remembering this wrong?
> 
> 
> 

You are remembering correctly, for the most part. 10k users are only throttled to 10 seconds per edit (unlike the 30 seconds for lower-rep users).

**Update.** We have been heavily discussing this issue internally recently, and we all agree that the current state of affairs sucks big-time. Ideally a human being would never see a captcha, and if they get one after all, it should be reasonably solvable. We're discussing several routes to go, but the bottom line is that our throttling/bot detection needs to become smarter.

For the time being, we've made a change that should at least heavily reduce this issue in the particular case discussed here (submission of edits). It should now\* be close to impossible for a 10k user and much less probable than now for a <10k user to hit this throttle during normal operation.

This is certainly not the end of it, merely a step, but I hope you agree it's the right direction.

\*next build
I honestly think that the only problem the editing system *might* be bringing to Stackoverflow is large-scale vandalism. When it comes to that, I believe there are three attack sources

1. Anonymous users
2. 2k- rep users
3. 2k+ rep users

The review system already tackles the first two. I personally think that it's highly unlikely that a spammer would train robot accounts until they have 2k rep so they can bypass the review system (think how hard it was to get your first 2k rep)

That's why I think that **5 seconds** is a very decent waiting time between edits and when you're gonna show some CAPTCHAs, why not a user-friendly one like [SolveMedia](http://www.solvemedia.com)

**Edit:** Don't get me wrong, I'm all for stopping spammers and whatnots. But do we (You, Stackoverflow) need to nuke the house just get rid of cockroaches?

**Edit 2:** @nhahtdh's scenario is a perfect example of when a CAPTCHA should be deployed, when there's a *suspicious* behavior.

The key here is gradually escalating the measurements:  

* 10 edit in 1 minute on different posts => suspicious => introduce CAPTCHA
* Same user did it again? Introduce CAPTCHA & Inform a moderator.
* Same user did it AGAIN? Suspend editing privileges.

In this case, you didn't annoy legit users AND minimized the damage of the **2k rep user** (and I don't think this will happen a lot).

Note: It took me 6 CAPTCHA retries to make this edit.