In theory you can change the licence and hope that those that use the software respect the licence terms, but that depends on trusting others.

I think of the case of the Russian programmer who was arrested and jailed for stealing proprietary code from Goldman Sachs. During the trial it was revealed that Goldman Sachs would use open source software and replace the software licence with their own:

"Open source was an idea that depended on collaboration and sharing, and Serge had a long history of contributing to it. He didn’t fully understand how Goldman could think it was O.K. to benefit so greatly from the work of others and then behave so selfishly toward them. “You don’t create intellectual property,” he said. “You create a program that does something.” But from then on, on instructions from Schlesinger, he treated everything on Goldman Sachs’s servers, even if it had just been transferred there from open source, as Goldman Sachs’s property. (At Serge’s trial Kevin Marino, his lawyer, flashed two pages of computer code: the original, with its open-source license on top, and a replica, with the open-source license stripped off and replaced by the Goldman Sachs license.)"

From: https://www.vanityfair.com/news/2013/09/michael-lewis-goldma...