Inform the neigbours of the portal in their vicinity.
A while ago, I talked to someone about Ingress. It took a while before he grasped what it was. That person also happens to be a police inspector. Then he said that once an a while they got calls of citizens. They all called, worried or alarmed about some stranger near their home, in the middle of the night, being busy with their phone. He found about about some "game", and was glad that finally someone explained the game to him.
I know we all find ourselfes at a remote portal, where sometimes we feel it must look suspicious what we are doing there at this isolated place and at this impossible hour.
I suggest that we create a leaflet template in several languages, with the photo of the portal, and some explanation what Ingress and that portal really is, and drop it in the neigbours' mailboxes. If we could generate it from the Intel Map application, that would be good.
One problem is to mark the fact that - per portal - it has already been done by an agent. Another problem is that a lot(!) of portal landmarks are removed - some even long ago.
So there you go. what do you think about this proposition?