Quick research sadly supports this heart breaking claim. 

The claim in the image about the scale of people killed by their own governments in the 20th century, compared to non-governmental murderers, is supported by substantial historical data and analysis, primarily defined under the term "democide." This term, coined by political scientist R.J. Rummel, refers to the murder of people by their government, including genocide, politicide, and mass murder.

According to Rummel's extensive research, it's estimated that governments have killed hundreds of millions of their own citizens throughout the 20th century, which is significantly higher than the number killed by non-governmental murderers. His work details numerous instances where regimes across various countries systematically executed massive numbers of their own people under different pretexts, such as political repression, ethnic cleansing, and consolidation of power.

The overall estimate is that governments murdered approximately 262 million people in what is termed "democide" during the 20th century. This figure surpasses the death toll from conventional war battles during the same period, suggesting a grave and pervasive threat posed by totalitarian and authoritarian regimes to their populations.

These findings emphasize the severe impact of government-led mass killings and raise significant questions about the role of government as a protector or perpetrator of lethal violence against its citizens. For further in-depth exploration of this topic, R.J. Rummel's book "Death by Government" delves extensively into the cases and data surrounding democide.