That's like outlawing knifes instead of murder. We should outlaw what the tech is used for, not the tech itself. Doing the later will just mean companies switch to other equally effective technology.
"It's not face recognition, it's a gait and hair identification system! We're breaking no laws..."
Certain technologies are simply too abusable to be unrestricted. In fact, many technologies only exist to do things we consider wrong, so we outlaw them. Granted, many times these laws are not well enforced.