As citizens online or in real life, how, or why, do the choices we make, almost always seems to have an effect (positive or negative) on others?

The choices we make as citizens online or in real life have both positive and negative effects on others because we are social beings, who live in an interconnected world. Every choice has some consequences on the decision maker or on others. We make the choices, but the consequences follow natural laws, which we cannot control. When Adam and Eve chose to disobey God, human beings down the ages lost their innocence and freedom. When the Nazis chose to purify their race of European Jews, there was the Holocaust between 1941 and 1945. When the Minneapolis police officer chose to slaughter George Floyd in cold blood, violent protests erupted throughout the U. S.

Another current example to buttress this is the ravaging coronavirus pandemic, which originated in Wuhan - China. When the Chinese Communist government chose to suppress the information about the virus as it usually does, the aftermath is the thousands of dead humans all over the world, the economic downturn, loss of jobs, virus infections with other public health side effects, plus many other untold consequences.

Had the Chinese government made a different choice, the virus could not have spread worldwide as it had. Similarly, some citizens online choose to circulate unverifiable ("fake news") information. Many people have been misled by their antics, some have lost their lives, while many others live in perpetual bigotry and hatred. All these are because of individual choices.

Explanation:

Choice is a concept in decision making. It is the judging of the merits of multiple options so that one or some of the options are selected. When a voter votes for one candidate against others, she has made a choice (decision). Of course, choices have consequences, which we must live with. Choices also define our present and our future.