WÜRZBURG, Germany — Anas Modamani, a Syrian refugee whose 2015 selfie with Chancellor Angela Merkel came to symbolize her decision to allow hundreds of thousands of unscreened migrants into Germany, is seeking to prevent Facebook from allowing users to repost the image after it repeatedly showed up in fake news reports.

The case is one of several high-profile cases against Facebook in Germany. Concern over nationalist and populist propaganda, as well as fake news, is growing in the country ahead of a general election scheduled for September.

The German justice minister, Heiko Maas, has suggested holding Facebook accountable for hate speech posted to its site, and a government-initiated task force that includes representatives from Facebook, Google and Twitter is examining how long it takes the companies to take down posts flagged as hateful. The panel is expected to report its findings in the coming months.

Who is Anas Modamani?

Mr. Modamani, now 19, fled Syria for Germany in 2015 and was living in a Berlin shelter when Ms. Merkel came to visit in September of that year.

The selfie that he took with the chancellor and that he posted to his Facebook page was widely shared on social media, and it became an emblem of her policy. Ms. Merkel’s stance on refugees has shaken her support, however, and it has helped fuel the rise of the populist, far-right Alternative for Germany party.

Why is he taking Facebook to court?

Mr. Modamani has filed for an injunction in a court in Würzburg, in the southern German state of Bavaria, that would require Facebook to remove any content linking him to terrorism.

His lawyer, Chan-jo Jun, says that although his client deleted the photograph and requested that it be taken down in some postings, it still appears on other people’s social media pages and in fake news reports linking him to terrorism. The image has been used with posts about the attacks in Brussels last year and on a Christmas market in Berlin. Recently, someone posted Mr. Modamani’s photograph on Facebook and said that he had been involved in a December attack in which a homeless man in Berlin was set on fire.

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Mr. Modamani’s lawyer says his client will continue to be a victim of libel until Facebook uses its algorithms to prevent the image from being reproduced.

What is Facebook’s defense?

The social media giant says that it is committed “to meeting our obligations under German law in relation to content which is shared by people on our platform,” and it has taken down images reported to the company by Mr. Modamani’s lawyer.

But Facebook says that the case involves defamation, not its community standards. That would mean the individuals who posted the images of Mr. Modamani would be held responsible, not Facebook.

What is Facebook doing to fight hate speech and fake news?

At first, the social network dismissed accusations that it had influenced the American election by spreading misinformation. But Mark Zuckerberg, Facebook’s chief executive, has since taken steps to bolster how the company handles such complaints.

Last month, Facebook updated its Trending Topics feature, which offers links to popular subjects, to better promote links to reliable news outlets. It also teamed up with news organizations, including The Washington Post, El País of Spain and the German nonprofit news organization Correctiv, to offer curated news reports to some of its 1.8 billion users. In France, Facebook and Google are working with domestic news outlets to ensure that fake news reports are not published on its platform.

Critics say those efforts do not go far enough, however.

What other legal battles is Facebook fighting in Europe?

This is far from the only legal challenge the social network faces on the Continent.

On Tuesday, an Irish court is set to decide if Facebook misused the digital data of Europeans by transferring it to the United States.

That case against Facebook, which has its international headquarters in Dublin, follows a European Court of Justice ruling in 2015 that invalidated a previous data-sharing agreement between Europe and the United States.

Privacy advocates say Facebook broke European data protection rules by moving users’ information across the Atlantic. The company denies the allegation. Legal experts say the case will eventually be sent to the European Court of Justice.