Anonymous threats sent by text message and email. GPS tracking devices placed under a car, and Chinese ¡°funeral money¡± sent to an office. Ambushes by reporters working for state-controlled media. Accusations of disloyalty in the press.

These are some of the methods deployed in a campaign of intimidation being waged against lawyers in Hong Kong who take on human rights cases, have criticized a China-imposed national security law or raised alarms about threats to the rule of law. While some of Hong Kong¡¯s leading rights lawyers have been detained in the past two-and-a-half years, many others have become the target of a more insidious effort to cleanse the city of dissent ¡ª part of a wider crackdown by the ruling Communist Party on lawyers across China, say activists, legal scholars and diplomats.

Michael Vidler, one of the city¡¯s top human rights lawyers, is among them. Vidler left Hong Kong in April, a couple of months after a judge named his law firm six times in a ruling that convicted four pro-democracy protesters on charges of illegal assembly and possession of unauthorized weapons. Vidler interpreted the judgment as ¡°a call to action¡± on the city¡¯s national security police ¡°to investigate me,¡± he said in an interview last month in Europe. He asked that his location not be disclosed.