Contains MNIST data from http://yann.lecun.com/exdb/mnist/.

You may download it yourself for example by

wget http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz