Did the TTI censor your *incoming* mail?

We are all familiar with the TTI's stranglehold on communication with people outside the program; how they limit it to the custodial parents and *maybe* with a minuscule list of pre-existing acquaintances pre-approved by your parents.

However...

I have also heard a great many disturbing stories (is there any other kind when discussing the TTI?) of programs censoring letters **from** home; blacking out references to friends and to family members other than the parents and maybe siblings.

Did this happen to you?

How common was it?

What was the rationale given?