Robertson's MP3.com was also sued back in 2000 by the major labels, and eventually paid out more than $100 million to settle copyright claims.
MP3.com was later acquired by major label Universal Music Group for $385 million.
"These guys rush off to court and tell the court that I am terrible, and then they end up buying my company," Robertson told Reuters.
"It is really a shame, because instead of using these technologies to improve their business, they make an enemy of every technology company out there."
Founded last year, MP3tunes sells DRM-free digital music, and lets users stream songs from online lockers, while Sideload.com lets users add free songs found on the Internet to those lockers.
In the current lawsuit, EMI claims that MP3tunes "does not own the music it exploits; nor does MP3tunes have any legal right or authority to use or exploit that music."
Robertson also told Reuters he believes that EMI's suit appears to have been filed in retaliation to a lawsuit MP3tunes filed against EMI in September, over a take-down notice it sent regarding Sideload — which EMI argued provided links to unauthorized downloads.