If you happen to see police scaling the cables of the Brooklyn Bridge: DO NOT BE ALARMED—it's planned!

The NYPD says that between 9 a.m. and 12 p.m. on Friday, the Emergency Services Unit will be climbing to the top of the bridge's Manhattan Tower for "training purposes only." The police routinely conduct these kind of exercises (feel free to share your photos or videos with us—email tips@gothamist.com or @ us on Twitter!)—here they are in 2016:

After a collective of German artists secretly climbed up the bridge to replace the American flag with a white flag in 2014, the NYPD increased security around the bridge. (The Department of Transportation also added gated doors on the cables to prevent trespassing.) Still, the allure of getting an awesome selfie for social media has convinced some tourists to get arrested for the 'gram.