Facebook is suspending Cambridge Analytica, a data-analysis firm that worked for the Trump campaign, while it investigates whether the company held onto improperly obtained user data after telling Facebook it had deleted the information. The social network said in a blog post that the firm violated its policies by receiving user data from a Facebook app created by a University of Cambridge professor. But while Cambridge Analytica certified in 2015 that it had destroyed the wayward data, Facebook said, the social network received reports “several days ago” that not all the data was deleted. Cambridge Analytica claims to build psychological profiles based on personal details from millions of Americans that can categorize individual voters. The company has surfaced on several occasions in probes of 2016 Russian election interference.