Spy vs. Spy

During US President Obama’s first term of office, Russian intelligence personnel had broken into the home of a US diplomat in Moscow and killed his dog. Source

In 2010, a Russian spy network often referred to as the “illegals program,” including 10 resident spies or “sleepers” living in the US (SVR’s “Directorate S”) was broken up by the FBI in “Operation Ghost Stories.” The spies were deported to Russia in a prisoner exchange. Wiki

In May 2013, US diplomat Ryan Fogle was arrested by Russian intelligence services as he attempted to enter the US embassy in Moscow. When he was arrested Fogle was allegedly carrying various disguises and spying tools. Source

In the period from 2014-2016, after strong US sanctions were implemented, Russian intelligence officials and security services engaged in a broad campaign of harassment and violence against US diplomats in Moscow and throughout Europe. US diplomats reported having tires slashed and being subject to routine harassment by police in Moscow. Government-paid protesters harassed former ambassador Michael McFaul and intelligence officers followed his children to school. Elsewhere, US diplomats had their homes broken into late at night, and in one example, an intruder had apparently defecated on the living room carpet. Source

On June 6, 2016, a uniformed FSB guard stationed outside the US embassy in Moscow assaulted a US diplomat attempting to enter the embassy. The US State Department complained about the incident to Russian Ambassador Sergey Kislyak. The reason for the attack is disputed, and the US has declined to disclose details, or whether the US diplomat was an undercover US spy.  Source

On December 28–29, 2016, in response to Russia’s interference in the US election, President Barack Obama expelled 35 Russian diplomats from the US as intelligence operatives, seized two Russian compounds, and imposed additional economic sanctions on Russia. The compounds had been suspected of being used for Russian intelligence since as early as the 1980s based on aerial and other surveillance. Source1 Source2