You're an idiot, don't understand how bitcoin works, or just want to steal customer funds. It's perfectly normal to spend an unconfirmed input. Sites that process many withdraws in a short period of time do it all the time, like my Cloudbet, Poloniex, Fairlay, e.t.c withdraws. If you're accusing them all of double spending (and probably many other sites as well), please find an transaction that they actually double spent and accuse them of it. It's pretty serious if your claim is real.