A voter-profiling firm that worked with Donald Trump’s campaign improperly obtained information on 50 million Facebook users, but experts say the data was both extremely valuable and possibly worthless. Cambridge Analytica, which worked with both Trump and Texas Sen. Ted Cruz’s presidential campaigns, got access to information on Facebook users and their friends through a researcher who misled the social network giant, saying the information he was gathering would be used strictly for academic research, according to recent reports. The trove included information like people’s names, locations, genders and things users have “liked” on Facebook, which a company whistleblower said it planned to use to exploit “the mental vulnerabilities of people” with targeted political messages. Because there would be no other way to get that data through Facebook, which does not sell personal information, it’s hard to put a price tag on how much it’s worth, sources in politics and tech say.