If you create or post one, remember to pay attention to the source of the image. Your best bet is to start with an image or clip that is already labeled for reuse or is in the public domain, meaning out of copyright protection altogether. Google Images search tools provides such a filter, or try the Creative Commons search for work licensed for reuse via Creative Commons licenses.

The viral spread of a meme infringes on theses protections as the original image is modified and then displayed, distributed and reproduced when posted and reposted.

“Some of what is happening now will make these white supremacists realize why their grandparents wore hoods,” Ms. Wilson said. “At least then there was shame.”

But Tony McAleer, a former white supremacist leader who now runs Life After Hate, a rehabilitation program for neo-Nazis, called doxxing a “ passive aggressive violence.”

To be clear, there is a law that defines domestic terrorism but not one that charges people who commit acts of terrorism in America.

Go up to the “omnibar” Strip off everything after the domain name, type wikipedia and press enter This generates a Google search for that URL with the Wikipedia page at the top Click that link, then check in the sidebar that the URL matches. Forty-nine out of fifty times it will. The fiftieth time you may have some work to do.