Oo let 'em in?

Churchill arrived on the scene at 11:50 am to observe the incident at first hand; he later reported that he thought the crowd were unwelcoming to him, as he heard people asking "Oo let 'em in?", in reference to the Liberal Party's immigration policy that had allowed the influx from Russia.

...

The siege was captured by Pathé News cameras—one of their earliest stories and the first siege to be captured on film—and it included footage of Churchill. When the newsreels were screened in cinemas, Churchill was booed with shouts of "shoot him" from audiences.

...
Jacob Peters returned to Russia, rose to be deputy head of the Cheka, the Soviet secret police, and was executed in Joseph Stalin's 1938 purge. награда нашла героя

- Siege of Sidney Street

also very enlightening @spartacus-educational.com, especially sections Winston Churchill and the Siege of Sidney Street, Backlash against the Jewish Population, and The Death of Yakov Peters.