The deadly shooting on Parliament Hill in Canada and hatchet attack on police officers in New York City–coupled with the Boston Marathon bombings and beheading in Moore, Okla.–represent the growing threat of lone-wolf terror attacks, the chairwoman of the Senate Intelligence Committee warned today.

Sen. Dianne Feinstein, D-Calif., discussed the continuing presence of these attacks on CNN’s “State of the Union.” Feinstein said the “multiplicity” of the attacks so far this year prove that the propaganda from Muslim extremists is working.

However, Feinstein noted that the Federal Bureau of Investigation is working to “find” and “stop” lone-wolf terrorists.