A group of four dozen Silicon Valley companies filed an amicus brief Wednesday in support of a California federal judge's decision to permanently block President Trump's executive order, which threatened to withhold federal funds from sanctuary cities.

Big picture: Most major tech hubs are also sanctuary cities, and the loss of immigrant talent and federal funding could be detrimental to companies in the tech industry. San Francisco and Santa Clara initially filed the lawsuit, which resulted in District Court Judge William Orrick temporarily blocking the order last April and then permanently blocking it in November. The Department of Justice appealed the both injunctions.

Who's backing it: The brief is missing big names like Apple, Facebook, Microsoft, Google and Salesforce, which have taken on the government in other cases. Among the biggest names on the list are PayPal, Airbnb