Actually you have a point, they cannot ban the gambling sites outside our country BUT. They can ban the bitcoin accounts that involves gambling. Example, here we are using coins.ph as bitcoin wallet. Once they traced that the transaction is from gambling. They are banning this account. And worst, the balance from that account is not refundable. Sad to those who lost their balance . That's how they control online gambling from other countries.
FYI Mark, Gambling is already against coins.ph TOS. Before signing up for a wallet you should read their TOS first to avoid problem. They will surely ban you if they trace that you are getting money from a gambling source be it with the Presidents order or without.
I've heard about Duterte guy, looks like he has lot of supporters in his fight against drug dealers in Philippines, but he also makes stupid decisions like this one, it will be impossible to ban online gambling since people will always find the way, I mean what he's gonna do, put giant firewall on Philippine internet like in China?
He's been hunting all the drug involved citizens right from his 1st day as a President. A lt of people has already dies and was put to jail, even police officials. I wouldn't be surprised if he will implement such big move on the internet if he wanted to.