Rusko's no stranger to speaking his mind when he feels wronged. He's the man who called the mau5 who shall remain nameless a "cunt" over a beef they had, but his twitter tirade on then-label Mad Decent was intense.
In March of 2012, about a week before the release of his album Songs, Mad Decent upload the entire album to SoundCloud, which many labels are apt to do in the age of streaming. This was not cleared with Rusko, and when he heard what happened, he immediately took his beef to twitter, with his anger escalating with each tweet. He went from being pissed that Mad Decent didn't clear the uploading of the stream to letting them know he wasn't re-signing when his contract was up later in 2012 (spoiler: he's on his own now).
His frustration made sense; once streams are up, nimble hackers will have the rips all over the 'Net. People aren't always wanting to buy stuff they've listened to over and over, and for Rusko to purposefully keep the album under wraps to have it uploaded by the label a week before release? Yeah, we feel his pain.