The "white slavery" (it was Christian slavery) practiced in North Africa isn't really analogous to African slavery practiced in the Americas. Not that anyone seeing the meme would know how to dispute the claims of the meme.
A couple of differences:
It wasn't generational slavery. Children weren't born slaves.
You could buy your freedom. Wealthy relatives or friends could ransom you.
You could get out of slavery by converting to Islam. It was called "going turk." Anderson Cooper's great great great great grandfather did this and became a Christian slaver himself.
At the end of day, being a slave sucks. Whether you're a white slave or black slave. Also the definition of slavery is in the eye of the beholder. Some say wage cucking is slavery, some would argue sweat shop working isn't slavery. Bleh, I can go on and on. Have done way too much studying on the history of slavery throughout the world. Slavery sucks