A law making it illegal to discredit Russia’s army has ensnared thousands of Russians for even mild acts or statements against the war.

In the past, the government would make examples of a few individuals, some prominent; now it is practicing widespread censorship. This year, with antiwar speech in public largely eliminated, the records show that authorities remained intent on stamping out criticism expressed online and in private. More than 3,000 cases involved social media or messaging platforms popular in Russia.