If this week taught us anything, it's that the brilliant shine around A.I. may finally be starting to fade. Investors are starting to realize that the reality of running an A.I. business is more than "train an algorithm, scale infinitely, profit." VCs at Andreessen Horowitz wrote this week that A.I. startups could be tougher than typical software investments: In addition to huge investments into cloud computing that many tech startups must make, A.I startups have the additional, hidden costs of labelling data, or the human task of looking at a picture, determining it's a picture of a bird, and typing the word "bird." Oh yeah, and there's the privacy concerns too -- see Alexa, Google Assistant, etc. And even when the initial algorithm is off the ground, exporting it to make it work in other locations or countries means labelling all over again in other languages.

In this Oct. 31 photo, a man has his face painted to represent efforts to defeat facial recognition. It was during a protest at Amazon headquarters over the company's facial recognition system. In this Oct. 31 photo, a man has his face painted to represent efforts to defeat facial recognition. It was during a protest at Amazon headquarters over the company's facial recognition system. San Francisco has become the first U.S. city to ban the use of facial recognition technology by police and city agencies.