Legal Question in Criminal Law in Massachusetts

The no trespassing sign isn't going to do you much good. That said, if this truly is a case of larceny (i.e., your siblings steal something of value from you, with the intention of never returning it), you arguably have a potential case to press charges. However, if you all live under the same roof, and your siblings are simply removing something from your room and taking it to another part of the house, that wouldn't likely qualify. For you to be able to successfully press charges, they would have to remove something from the house without your permission, with the intention of never returning it to you.

lock your door