Trust thou not in fake memes – Not William Shakespeare] Mark Shea was expressing his frustration over people who generate fake memes by taking a phony quote, pasting the quote onto a photo of Pope Francis, and attributing the phony quote to the Pope.
Someone left the following in the comment box:
"The problem with Internet quotes is that you can't always depend on their accuracy." - Abraham Lincoln, 1864
I remembered seeing that quote before. I was reasonably certain that I had also seen the joke used as a quote from other famous (and infamous) pre-Internet folk.
I've gathered a few of the memes from Google Images and added a few of my own.