WASHINGTON — Facebook is being asked to change rules that restrict how journalists and scholars conduct research on the site — a request that raises unresolved issues about how the First Amendment applies to the social media era. In a letter sent Monday, lawyers for a group of researchers and journalists asked Mark Zuckerberg, Facebook's founder and chief executive, to alter the agreement that people must adhere to to use the site. They want Facebook to create a news-gathering exception to its bans on creating inauthentic accounts and on using automated tools that scrape public data about users for large-scale analysis. The request comes as Facebook has stepped up enforcement of such rules because it is under intense scrutiny over its failure to stop Russia's use of fake accounts to stoke tensions and manipulate the 2016 election, and over the revelation that the now-defunct political-consulting firm Cambridge Analytica acquired and mined millions of Facebook users' information to help the Trump campaign.