The company laid out that the legislation would affect its fans in a number of ways. It's concerned about streaming services being shut down for non-malicious use of copyrighted material, and the threat such laws would have on creation and sharing sites such as YouTube, Reddit and DeviantArt, along with streaming websites, including Own3d and Twitch. In-house, Riot notes features such as in-game chat and forums could be cut back to avoid potential threats.
Riot is not a member for the ESA, the video game industry's political arm, which is in support of the legislation.
Riot also mentions that both acts "raise serious constitutional free speech issues, and could even compromise the basic security infrastructure of the internet." The statement concludes, "While we do support efforts to prevent online piracy, the current form of this legislation comes at far too high a cost for us, our players, and online communities across the internet."
(As an aside, Riot's attorney is currently answering almost anything on Reddit right now about the company's stance.)