Every time that I'm not logged in (or at least in a browser that has not been logged in since a cookie clear / in a private window) and I make a search on a Stack Exchange site via DuckDuckGo, I am presented with a CAPTCHA. This is strange, however, as if I go directly to the URL of a search, I get no such CAPTCHA.

For example, if I search on DuckDuckGo

>Is there an R function for finding the index of an element in a vector? !so

I get a CAPTCHA, but if I type directly into the address bar

>https://stackoverflow.com/search?q=Is+there+an+R+function+for+finding+the+index+of+an+element+in+a+vector%3F

I do not. 

Watching how [DDG bangs][1] work with the following `curl` command, we see that it is not an HTTP redirect, but presumably JavaScript:

>curl -v -A 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:84.0) Gecko/20100101 Firefox/84.0' 'https://duckduckgo.com?q=Is%20there%20%20an%20R%20function%20for%finding%the%20index%20of%20an%20element%20in%20a%20vector \\!so'

Result (relevant bit, and run in `zsh`):

> < HTTP/2 200 

It's kind of annoying that I have to fill out a CAPTCHA or log in every time I do this, even though it can be avoided by simply using the search bar on SO. Can something be done to prevent the CAPTCHA from being presented every time this happens?


  [1]: https://duckduckgo.com/bang