@Kristin That particular offence is not very common and also new. I think you are referring to a conviction under:
162.1 (1) Everyone who knowingly publishes, distributes, transmits, sells, makes available or advertises an intimate image of a person knowing that the person depicted in the image did not give their consent to that conduct, or being reckless as to whether or not that person gave their consent to that conduct, is guilty
(a) of an indictable offence and liable to imprisonment for a term of not more than five years; or
(b) of an offence punishable on summary conviction.
Homeland Security is probably having trouble assessing the seriousness of the offence. Remember, despite your obvious attempt to shame people you feel that "had it coming", this legislation exists because of this:
Rehtaeh Anne Parsons (/rəˈteɪə/, rə-TAY-ə;[1] December 9, 1995 – April 7, 2013), was a 17-year-old Cole Harbour District High School student who attempted suicide by hanging[2] at her home in Dartmouth, Nova Scotia, Canada, on April 4, 2013, leading to a coma and the decision to switch her life support machine off on April 7, 2013.[3] Her death has been attributed to online distribution of photos of an alleged gang rape that occurred 17 months prior to her suicide, in November 2011.[3][4] On a Facebook page set up in tribute to her daughter, Parsons' mother blamed the four boys who allegedly raped and released images of her, the subsequent constant "bullying and messaging and harassment", and the failure of the Canadian justice system, for her daughter's decision to die by suicide.[5]
Unfortunately, you are going to get lumped into the same category as men who use these images to blackmail sometimes very vulnerable victims. I hope you got some skilled help with the personal letter. This is NOT a simple waiver at all.