Few examples:
1. Online troll bots & fake personalities
It's going to get a *lot* harder to distinguish bots from people and much easier to create entirely fictitious credible online personalities to troll/harass/do crime
2. Persuasive letters by e.g. constituents to regulators.
Volume of (~sensible, unique) letters was a valid indication of sentiment. Soon won't be.
3. Ransomware victim communications & negotiations
Used to be one of the few costly areas in scale. Not for long