Just explained this on another thread. I'll copy and paste it here.
The so called "jack attack" isn't new at all. It's been around for awhile and personally I don't see it working. I think any success with it is coincidental. I will explain it.
Supposedly you would DV the CA which would time bar them from collection activity. Then you would dispute it. The premise is that they would not be able to verify the debt because of the DV. This is false. They can still verify it, even by e-Oscar.
This has been discussed before, but I figured it had fallen from favor because I haven't seen it discussed in quite some time.
I had just finished reading your explanation on the other thread. Seems like it's a waste of time. If the CA does verify, then you've gotten nothing accomplished and created more hills to climb.
It used to be a popular subject, especially on another site. And yes, if it did work, it would be an exploit, and I wouldn't be able to talk about it here.