security after enabling query strings

[eluser]learnq[/eluser]
Hi,
I have to enable query_strings for paypal &other;payment getway as they return
through GET.
Now , as I enable query strings CI do not filter the datas by default.
If I take all data like

Code:

$name = $this->input->post('name',TRUE) ;
$name = $this->input->get('name',TRUE) ;

am I safe ? If not, how can I filter the data in better way ?

Thanks.