This week, two years after being widely panned for a filter that critics described as little more than “digital blackface,” Faceapp, a photo-altering smartphone app, found itself at the center of a popular social media challenge.

On Wednesday afternoon, the Democratic National Committee even sent out an alert, urging staff members on presidential campaigns to delete the app immediately, citing its ties to Russia, according to CNN .

But Ivan Rodriguez, a software engineer at Google who in his free time investigates suspicious iOS apps, including FaceApp, said he found little cause for concern.

Mr. Robert and two other researchers who investigated the issue all said they had found no evidence on Apple or Android phones that FaceApp was secretly uploading entire photo galleries.

“If they don’t take Privacy seriously, how seriously do they take security?” asked Will Strafach, the founder and chief executive of Guardian Firewall, a tool coming soon for iOS that aims to give users more control over their data.

“The fact that a lot of apps and services usually contain this catchall clause that says you grant us worldwide license to reproduce, modify, adapt, create derivative works from, distribute, publicly perform and display your user content always seems a little over the top to me.”