Clinic blockades nearly doubled. Arsons and bomb threats quadrupled. Acts of vandalism went up fivefold. Threats of bodily harm increased by 94 times. And an armed gunman named Robert Lewis Dear killed a police officer and two civilians inside a Colorado Springs Planned Parenthood clinic, later proclaiming himself “a warrior for the babies.”

All together, 2015 was the worst year in history for anti-abortion violence, according to a new report compiled by the National Abortion Federation (NAF). For NAF, which has been collecting statistics on anti-abortion violence since 1977, the reason for 2015’s extreme level of violence couldn’t be clearer.

“The sharp rise in threats and violence in 2015 is alarming, and directly correlates to the release of inflammatory videos aimed at demonizing providers,” said Vicki Saporta, president and CEO of NAF, in a statement. “In my more than 20 years with NAF, I have not seen such an escalation of hate speech, threats, and calls to action against abortion providers.”

Last year’s undercover video smear campaign against Planned Parenthood, spearheaded by anti-abortion activist David Daleiden, immediately preceded this dramatic increase in violence against abortion providers.

The year before Daleiden’s Center for Medical Progress (CMP) released videos falsely alleging that Planned Parenthood sold fetal tissue for a profit, abortion providers received nine suspicious packages or hoax devices. Then, in 2015, they received 35 of these packages. In 2014, there was a single recorded death threat or threat of harm against an abortion provider. In 2015, there were 94 such threats.

Violence increased from 2014 to 2015 in several of the major categories that NAF tracks. Stalking incidents doubled from four to nine, burglaries went up from one to nine, acts of trespassing rose from 78 to 118, and picketing incidents increased from over 5,000 to over 21,000.

The most shocking spike was recorded in the category of hate emails and Internet harassment, which is notable given the viral spread of the CMP videos. In 2014, NAF recorded 91 occurrences of Internet harassment against abortion providers. In 2015, there were 25,839.

2015 also saw the most anti-abortion murders since 1994 and the first since Dr. George Tiller was murdered in Kansas in 2009.

The sharp rise in anti-abortion violence in 2015 didn’t properly begin in January—it specifically followed Daleiden’s undercover campaign in the summer.

As The Daily Beast reported last December after the Colorado Springs shooting, NAF, the FBI, and Planned Parenthood had all warned of an increase in violence after the CMP videos were uploaded to YouTube, beginning on July 14 last year.

In a July 31 application (PDF) for an injunction against Daleiden and the CMP, NAF noted that “incidents of harassment at Planned Parenthood facilities increased ninefold in July, compared to reported incidents in June, and the reported incidents of harassment were even more numerous in August.”

After Dear was arrested in November for killing three and wounding nine inside a Planned Parenthood clinic, law enforcement officials told NBC News that the gunman said, “No more baby parts” after his arrest, an apparent reference to the title of the first CMP video and the #PPSellsBabyParts hashtag through which it spread on social media.

“In the last year, we’ve seen the consequences of this firestorm of hate firsthand,” said Saporta in the NAF statement. “When abortion providers are targeted and demonized, clinic staff are threatened, facilities are set on fire, and doctors are murdered.”