Willi Kuhlmann remembers the day the Berlin Wall was erected on Aug. 13, 1961, and how the system of spying on East German citizens by secret police known as the Stasi intensified.

His experience as a border guard along the Wall that divided Germany’s capital city for 28 years makes him mistrustful of the data-gathering carried out by the U.S. National Security Agency, revealed in a series of disclosures to publications including Germany’s Der Spiegel by fugitive Edward Snowden in recent weeks.

Kuhlmann, a 77-year-old retired forester, is among ordinary Germans who draw parallels between the NSA’s activities and the surveillance carried out by the Stasi. One in two of the country’s citizens regard Snowden as a hero, according to a June 29 survey of 504 people by Emnid for Bild am Sonntag newspaper.

“You don’t spy like that on your friends,” said Kuhlmann in a telephone interview.