Facebook sites for themselves, where even the hard and unpopular questions can be asked. Those that have done this (from all parts of the political spectrum), should be congratulated for their openness, and promotion of true democracy. However, some incumbents are either deleting the difficult questions from their Facebook page, and "Banning" the people that ask them, or they don't have a public Facebook page at all. This isn't good for the voters, as it excludes them from direct interaction.
However, unofficial Facebook pages are a way of addressing this problem. It goes without saying that politicians, just like anyone else, shouldn't tolerate untrue and libellous statements, or posts that are sick and/or abusive. Of course that kind of thing should be deleted and banned. But they should be directly accountable to the people for legitimate questions, now that we (at last), have the technology to allow that.
We can inform our local politician of their "Unofficial" page, and draw their attention to the concerns and/questions we've posted, and leave the rest up to them. If they choose to ignore it, so be it, but their avoidance will be visible to the World.