How to check if any variable is being passed to GET in URL

I have a situation where someone is trying to sabotage my google adsense account by continuously sending personally identifiable information into the URL to my site. How can I block this or at least detect the random variables they are using?

For example, the variable name could be ANYTHING.

mysite.com/[email protected]

...?

The only thing I can think of doing is collecting known variables and then perform a header location redirect to the main site URL.

Solution

If: you want to have no GET parameters, check if $_GET is empty

if (!empty($_GET)) {
    header('Location: ' . $_SERVER['SCRIPT_NAME']);
    exit;
}

Or: check $_GET for non-allowed parameters:

$allowed_params = ["id", "some_param", "another one"];
foreach($_GET as $key => $val)
    if (!in_array($key, $allowed_params)) {
        // if something's wrong, get out!
        echo('Location: '.$_SERVER['SCRIPT_NAME']);
        exit;
    }

// everything is ok here

Note: before any header()s you mustn't have any output. Otherwise you'll get an error. Better place the code in the very top of your script.