Call me paranoid but why do the staff on a lot of private trackers seem so interested in what other trackers you have accounts with?

Most of the time when you apply with a new tracker or have to re-apply due to inactivity it feels like you're being interrogated by the feds.

From the perspective of a private tracker, why are they so pushy about that? And can they know if you're lying?

The implication seems like, "we all talk to each other and if you lie to me you lose all of your accounts".