Since Donald Trump's election, many in the tech industry have been concerned about the way their skills—and the data collected by their employers—might be used. On a number of occasions, Trump has expressed the desire to perform mass deportations and end any and all Muslim immigration. He has also said that it would be "good management" to create a database of Muslims, and that there should be "a lot of systems" to track Muslims within the US.
In the final days of his presidency, Barack Obama has scrapped the George W. Bush-era regulations that created a registry of male Muslim foreigners entering the US—the registry itself was suspended in 2011—but given Trump's views, demands to create a domestic registry are still a possibility.
As a result, some 2,600 tech workers (and counting) have pledged both not to participate in any such programs and to encourage their employers to minimize any sensitive data they collect. The goal is to reduce the chance that such data might be used in harmful ways.