<human>: Can you provide a brief rundown of the text in within 3 sentences?

Here's the story: The previous tenants of the apartment I'm in now left a nearly brand-new couch when they left. They moved out in July, I moved in toward the end of the same month. I had talked with them about getting their shit out -- the couch and bunch of other junk in storage spaces in the apt.; at first they told me to just keep the couch, they didn't feel like moving it. I thought that odd, but whatever, free couch! Couple days later they renege; turns out it's the guy's sister's couch, and she's pissed he gave it away. Fine, whatever. I'm getting tired of dealing with these idiots, and so try to set some dates where the dude could come haul it out.

Well, he's impossible to get a hold of. I call and call to no avail. I give up. Couple days later, he rings me up randomly, we set a date and time. Date and time come and go, no sign of the dude, no answer on his cell. This exact scenario happens once again about a week later. I say fuck it, I'm not spending anymore effort on this. I let my landlord know, he says to have them contact him if it comes up again, I begin using the couch in the interim. 

Flash forward to last night: I am having a small party. At about 8:30 at night two scummy-looking dudes that I've never seen before in my life show up at my door with a u-haul parked on the street looking for the couch. I politely tell them to talk to the landlord and close the door in their faces.

Anyhow, I've been wondering what, if any, claim they have to this property at this point. I've been trying to negotiate my state's laws (This is in Massachusetts, by the way) but I'm not having much luck. Any landlords or lawyers or someone with similar experience have any insight?
<bot>: previous tenants left a couch and some other shit for six months. i kept it. now they want it back. what should i do?