Inconsiderate, Overbearing Landlord: Help?

My family rents. There is a garage on the property that the landlord won't let us use, he uses it for storage. Well, he and his son and anybody else they want use it, that is. We have people show up at our house waking us up, after midnight, and even worse, see people we've never met outside our home at any given hour. This is getting out of hand, we almost called the cops because we had no idea who these people were poking around our home! The landlord himself shows up at random times without calling: just standing outside next to a window when you've just gotten out of the shower...please tell me I can do something about this! We have no privacy anymore!