Pope Gregory III declared that November 1 as "All Hallows Day" in the Church calendar. As such, the night before, October 31st, becomes "All Hallows Eve". Just like we make a big deal about Christmas Eve, so too the Church made a big deal about All Hallows Eve.
The Church created Halloween. It is a celebration of those who have died and a preparation of the All Hallows Mass that is the next day.
Over time Halloween is co-opted by secular motivations and now we have a sugar driven market "holiday" that is as far removed from the reverence of All Hallows Eve.
Halloween, in this respect, is just like Christmas. The Church no longer has the claim on Christmas. It is now removed from the Church in such a way that our economy actually depends on the commerce of Christmas - beginning in November.
For as far as Halloween as drifted from the Church calendar, the Church seems to be making steps to reclaim Halloween via Trunk or Treat.
I know moving to the church parking is does not change the "idolatry of sugar" and trunk or treat looks, on the surface, just a more efficient way to get candy. What I want o highlight is that the Church is impacting culture in a way and at a scale that the Church used to do with greater frequency.
When the Church is responsible for changing customs, traditions and habits (even in the practice of Halloween) then the Church is reclaiming its role as a culture maker.
For all the condemning of the consumerism of Christmas. For all the critiques to "put the Christ back in Christmas". These actions have little effect on the practice of Christmas. If we want to change the way we practice Christmas, then we need to create a new way to practice Christmas.
If we really want to be sure we all remember "the reason for the season". Don't change your profile picture.
Instead take a page from Halloween and change the way you practice Christmas.