Some of the leagues that have yet to have a full season with Periscope in the mainstream are taking action to stop it. While NFL spokesman Brian McCarthy said the league was not worried about Periscope, the NFL has filed four copyright take-down requests to the app, according to the website ChillingEffects.org, an archive founded by Wendy Seltzer of Harvard’s Berkman Center for Internet & Society.

Source: Sports league keeping an eye on Periscope, Meerkat