CAPTCHA before Get

Many times we allow a value to be entered in a field and then perform a GET operation, according to the value.

It can be a social security number or any other unique number.

One of the claims of information security experts, and rightly so, is that this allows bots to attack.

It would be useful if it would be possible before the GET operation to oblige the user to use a CAPTCHA before (Google,ABN,NZBN etc.).