Fake reviews used to be crowdsourced. Now they can be auto-generated by AI, according to a new research paper shared by AmiMoJo:
In this paper, we identify a new class of attacks that leverage deep learning language models (Recurrent Neural Networks or RNNs) to automate the generation of fake online reviews for products and services. Not only are these attacks cheap and therefore more scalable, but they can control rate of content output to eliminate the signature burstiness that makes crowdsourced campaigns easy to detect. Using Yelp reviews as an example platform, we show how a two phased review generation and customization attack can produce reviews that are indistinguishable by state-of-the-art statistical detectors.

Humans marked these AI-generated reviews as useful at approximately the same rate as they did for real (human-authored) Yelp reviews.