I find this slightly less evil then standard tracking, because information is not shared with a third party. That being said, I think there's a line. If you us

I find this slightly less evil then standard tracking, because information is not shared with a third party. That being said, I think there's a line. If you use it to gather the exact same info as server log's, except with bot's filtered, that seems perfectly reasonable. If you use it to track everything a user does on your page, that seems fairly evil.