Edit: not to mention the worse damage will be from fraudsters taking loans.
The weird thing is the Comcast debt couldn't have actually been mine. As the date of the debt was smack dab in the middle of when I had service with Comcast before switching to ATT.
Now, during this period I tried to refinance my home and was denied due to a low score with Equifax. I pulled my EQ 2 weeks before trying to qualify and there was nothing. Then I found that after I was denied and pulled it again of course. I submitted a challenge on it, and it was removed within 2 weeks but the damage was already done.
So would this count as real damages?
Whether the debt "could have been yours" isn't relevant, what's relevant is how it showed up there. If someone fraudulently signed up for a Comcast account using your social, and they obtained your social via the leak, then yes the leak damaged you. You could go after the difference in your refinanced interest rate now v. what it would have been had you gotten it at the first request (are you paying 0.1% more because rates went up a week after your denial?) and possible the additional interest paid between the denial and the successful refinancing.
But if the Comcast account showed up on your report because someone fat fingered a social and there was no fraud, the leak didn't damage you at all and it was just bad luck.