Here's a summary of the article:

A Bulgarian spy ring was caught by British authorities after gathering intel on investigative journalists Christo Grozev and Roman Dobrokhotov, who had reported critically on Moscow's actions. The spy ring, led by a man named Rousseff (also known as Roussef), targeted Grozev, a journalist who exposed Russian links to the 2018 Salisbury poisoning attacks, as well as Dobrokhotov, a Russian-born editor-in-chief of an investigative outlet.

The group also spied on a US military base in Stuttgart, Germany, and caused chaos by spraying fake pig blood at the Kazakhstan Embassy in London. They used a variety of sophisticated surveillance technology to gather intel, including cameras and microphones.

Russian intelligence agencies are increasingly using proxy agents like this Bulgarian spy ring to gather intelligence, as Moscow's diplomats and spies were expelled from over 700 countries after its invasion of Ukraine. These agencies often recruit online through messaging apps like Telegram.

Experts say that the use of proxy agents is becoming more common and effective for Russian intelligence, as it allows them to operate in Western societies without being detected. The success of this operation suggests that Russia will continue to view its work as a success, even if it didn't have to sacrifice any nationals to gather the intel.

The head of the CPS Special Crime and Counter Terrorism division described the espionage operation as "high-level" with "significant" financial rewards for those involved. Frank Ferguson said that the spy ring's targeting of journalists who had fled persecution in Russia undermined the message that the UK was a safe place.

Investigative journalist Christo Grozev, whose story was targeted by the spy ring, said: "This is a chilling message to Russian citizens who are living under threat from their own government." Dobrokhotov added that he was lucky not to be harmed and would continue to work on exposing Russia's activities.