I guess you could consider Paypal/Venmo which scan for words: https://slate.com/technology/2020/02/paypal-venmo-iran-syria...
Another is that Google Photos and Facebook both do classification for objects and text within photos - eg. a Kohl's ad in my timeline on Facebook has image alt text of "May be an image of 1 person, standing, footwear and outdoors". I'm sure their detections look for TOS breaking content or other pictures showing illegal activities.