As an @jack…I agree
Discussion
On Bogbook awhile back I had someone coming on and identifying as @ev, which looked exactly the same as my handle, which is @ev, and then pretending to be me while I was sleeping.
The solution I came up with was to provide a small in-line public key hint:

After I did that whoever it was cut it out, because everyone could see he had different public key than my own.
Impressive 
Jack with a Spanish accent sounds like hack 🤔