I really don't understand lazy censoring. You can either not use the thin pen tool or just spend a few more seconds making sure it's unreadable. What's the point of doing it at all if people can still decipher what you're obscuring?
I agree with the other reply and would honestly love an answer, if only to get a peek under the hood of people who do this.
If you didn't try that hard because you didn't care, again, why did you even bother? It's like trying to scoop water with a colander, on some level you have to know it's wasted effort, right?
its more than likely "it can't hurt, so might as well" more than anything.
If they really didnt want it, they wouldn't have posted this at all, or like other suggested properly censored it, they simply tried here, deemed "most people won't bother" and moved on from it.
In general I think best practice is to call out “hey, I can see your area code in case you want to edit your post to more fully redact it” then any jokes about “since I wouldn’t want anyone to know I lived in [REDACTED] either!”