Definition: Given a document, generate a short title of the document. The title should convey the main idea/event/topic about which the document is being written. Note that URLs in the text have been replaced with [Link].
Input: In the wake of the Russian troll campaign against Ukrainian activists  several Facebook users brought up the issue to  Facebook co-founder and CEO Mark Zuckerberg  when  he  called for questions to be submitted prior to a May 2015 town hall  the report found.
 Zuckerberg  touched on the issue during  his  town hall in May 2015 and said that several posts that had been flagged contained "hate speech" and anti-Russian "slurs."
" We  did the right thing according to  our  policies in taking down the posts. I support  our  policies in taking down hate speech "  he  told attendees.
 Zuckerberg  extended an apology to users whose posts had been taken down despite being in compliance with community standards  and attributed the error to a bug in Facebook's software.
Former President Barack Obama tried to warn  Zuckerberg  about the threat of fake news and  its  effect on the 2016 election less than two weeks after Donald Trump won the presidency The Washington Post reported on Sunday.
Nine days before Obama warned  him  about the effect fake news had on the November result and the problem it would pose in future elections   Zuckerberg  struck down the notion as a "crazy idea" that "surely had no impact" on the end result.
Following the president's warning   Zuckerberg  acknowledged the problem but said fake news wasn't widespread on Facebook  according to The Post.  He  added at the time that there was no easy solution to the issue  according to those familiar with the matter.

Russian trolls used Facebook to undermine Ukrainian activists years ago