I’m curious whether there’s a big overlap between people that the FBI is interested in and people who care about grammar. That’s not a flippant response: I’m genuinely curious if that is part of a shift towards white collar crimes (which could be welcome) and more generally criminal psychology.
I’ve been watching _The Wire_ and Idris Elba’s character sounds like a good overlap, but he feels very unusual (in fiction)--and definitely too careful about OpSec to use that kind of service.
More generally, there’s a lot of anecdotic evidence between problematic behaviour and low-level spelling details: one that is apparently better documented now is a correlation between insurance fraud and whether you capitalise properly the name of your employer on registration form.
It is perfectly possible to be a grammarly user and not upload everything to it, but if I am running a script or draft of a blog post through it, what harm is there?
Come to think of it, that'd be the perfect place to go to demand a wiretap - at least one such popular "LY" service already exists.
I'm still shaking my head at what many regular users will agree to..