There has to be some way to remove constructs/buildings etc. of people that no longer play.
Does anyone else remember cities and cities of ghost-towns in SWG? I do. I don't want that.
So I propose something along the lines of - if you cancel your subscription, then one month after your last paid date, all your stuff gets packed up and put in your inventory.
Should you re-subscribe at a later date - then you need to find a new place to put your stuff down.
Don't like it? Then don't cancel.