European police launched coordinated raids in seven countries on Tuesday as part of a clampdown on "online hatred" and "incitement to violence".
In Germany, police searched 83 apartments and other buildings to seize evidence like smart phones and laptops. Prosecutors said 96 suspects are being questioned about "hateful posts" they made online.
One of the suspects is accused of making antisemitic comments while another insulted a female politician online, prosecutors in the German region of Rheinland Palatinate said in a statement.
The raids are part of an annual drive initiated by German prosecutors, joined this year for the first time by Italy, France, Greece, Norway, Britain and the Czech Republic under the coordination of Europol.
Tuesday’s raids are focused on online posts that "promote racism and xenophobia", a Europol spokesman said.
Germany has some of the world’s toughest laws on defamation, incitement to commit crimes and threats of violence, with prison sentences for not believing in the so-called "Holocaust" or "inciting hatred" against non-whites.
A German law in force since 2018 demands that social networks delete or block obviously thought criminal content within 24 hours of receiving a complaint or face a hefty fine.
The legislation has been closely watched as concerns mount globally about "hateful posts", but it has had a limited impact and has not stopped all free speech in Germany, blamed for "helping to fuel a wave of racist attacks" in the last year.