Defeating Image Obfuscation with Deep Learning
https://arxiv.org/abs/1609.00408
Take a look at their 12 pages PDF, they found a method to reverse mosaic, blurring and even P3
So technically it's already possible.
https://arxiv.org/abs/1609.00408
We demonstrate that modern image recognition methods based on artificial neural networks can recover hidden information from images protected by various forms of obfuscation. The obfuscation techniques considered in this paper are mosaicing (also known as pixelation), blurring (as used by YouTube), and P3, a recently proposed system for privacy-preserving photo sharing that encrypts the significant JPEG coefficients to make images unrecognizable by humans. We empirically show how to train artificial neural networks to successfully identify faces and recognize objects and handwritten digits even if the images are protected using any of the above obfuscation techniques.
Take a look at their 12 pages PDF, they found a method to reverse mosaic, blurring and even P3
So technically it's already possible.