The BBC piece is vague on how the choice is to be made, simply saying that the choice will be offered to customers as they sign up. The Globe and Mail piece says similar things.
The concern is that it is a choice during activation, versus a direct opt-in to the controls (or worse, a default state of "on" with a requirement to opt-out).
To me, any sort of explicit control or filtering of content should be at the discretion of the user to opt into. I don't have a problem with educating subscribers as to the options, but I can definitely see issues with pressure by spouses/family to opt into controls when an explicit answer has to be given, even if such controls aren't warranted in the household.
Just seems like nanny-state-ism to me. Don't want your kids to access potentially pornographic materials? Two options: first, educate your damn children instead of relying on technology, then consider implementing your own behavioural solutions.
I don't care what blocks are on content, people who want porn will find it. Parental control software strikes me as largely laziness, and fairly ineffective (and when my children are at an appropriate age, I intentionally will NOT be installing it).