As you probably know, logic for adding Mods in the Ingress game now changed.
You can get 125AP now for placing one Mod (there was AP reward long time ago, but it was removed after abusive activity from some players), but at the same time can only place two per portal and cannot remove them at all.
This seems logical, though makes rural players to struggle, as they will have hard times shielding all their portals. Anyway, Niantic still tries to find the best balance and we can only welcome their efforts.
Also, I believe, some game rules will be changed all the time to match the main Shapers story, published by Chapeau.
