Hong Kong pro-democracy, anti-Beijing activists are on edge since this week’s formal passage of the sweeping national security law in response to the mass protests and unrest which gripped the city for much of last year.

As we and many others detailed of the law which went into effect Wednesday, it harshly cracks down on dissent with possible maximum life jail sentences for some crimes, largely dependent on the ambiguous and highly open to interpretation (with no independent review) question of what constitutes ‘foreign interference’ or sponsorship of a ‘terror’ organization.

Already some among protest leaders are fleeing in fear for how the law might apply retroactively to their past activities, as well as current activism. For example it’s already spooked a prominent young pro-independence leader named Nathan Law.

“He announced he had left two days after China brought in its new security law,” BBC reports. “Activists say it erodes freedoms but Beijing has dismissed the criticism.”

Law issued a short message announcing his departure: “I have already left Hong Kong and continue the advocacy work on the international level,” he said in English, though without specifying which country he would settle in.

“Based on risk assessment, I shall not reveal too much about my personal whereabouts and situation now,” Law’s message added. After previously spending time in prison for leading protests in 2014, he’s not taking any chances apparently, also given his public links to Washington.

Both he and HK’s other most visible independence movement activist, Joshua Wong, have been seen as close to State Department and US embassy officials, even lately briefing Congressional leaders on the new security law:

Within moments of it being announced on Tuesday, Mr Law said he was stepping down from Demosito Party, which he co-founded with well-known activist Joshua Wong. At the time, he said the law marked the start of a “bloody cultural revolution”.

On Wednesday, Mr Law spoke via videolink to a US Congressional hearing on Hong Kong. He told American politicians he was worried about returning to the territory, for fear of being imprisoned by Beijing.

Pro-Beijing officials and media previously accused the pair of being stooges of the US and Britain, doing foreign bidding under the guise of local activism.

No doubt in the eyes of the mainland’s Communist Party, this might be enough to get him locked up on “foreign sponsorship” related to his protest activities.

t’s more than likely we’ll see other big activist names flee Hong Kong and the region in the coming days and weeks, also as it’s still a bit up in the air as to what the new law’s application will look like in practice.

Clearly pro-independence leaders are bracing for the worst.