Yes, but I also believe it's less as a proportion of population than it's ever been in the history of the world. There are approximately 7.3 billion people in the world[1], and there are over 35.8 million people in slavery[2]. That's less than half of one percent. But that doesn't matter, because slavery is bad, so
any slavery, regardless of the amount is bad. So it could be 100 people in the world are enslaved, and we would still need to do something about it.
But that's irrelevant. This is about terminology and wording. Do you really think anyone that's an actual subject of slavery cares if master and slave are used in some esoteric context to describe the relationship between inanimate objects and processes? Do you think they would prefer people spend their time arguing over this instead of actually doing something about the problem? The last thing we need is to cleanse our vocabulary of these terms. If we actually want to make a change, hiding is not the correct thing to do.
Armchair terminology censoring isn't actually doing anything to help the problem, it's just providing a way to make people feel like they are helping without actually addressing any part of the real problem. Ultimately it's not just ineffective, but since it fulfills people's desire to feel like they are making a difference it's actual harmful in that it prevents some people from actually getting to the point they would do something.
To make my point absolutely clear, using master/slave as a terminology to describe non-sentient processes is in no way condoning slavery, does not affect slavery, and does not harm anyone. Artificially linking the this concept with actual human slavery and the slave trade for the purpose of denouncing it is selfish, dishonest, and harmful. That said, I don't think most people are necessarily conscious of what they are doing when doing so, but that still leaves us with harmful.
1: http://www.worldometers.info/
2: http://www.globalslaveryindex.org/