Check a game for cheating
@AleksandrAgishev Use engine analysis function (analysis board). If your browser is compatible with Stockfish 11+ WASMX or Stockfish 10+ WASM, great, press the analyze button and if your opponent has a centipawn loss of under 15 there is a high chance of cheating. That doesn't mean everything though, I think you should check your opponent's other games too. If you really think someone is cheating then report them to moderators immediately, or post it in the "lichess feedback" forum so everybody can see. I hope this helps.
@tpr Exactly. Also, you can go to that user's profile to block them and press the report button.
You can't post in the forums yet. Play some games!