This market will resolve to "Yes" if the Telegram app is banned for download and/or use by the majority of citizens in any European Union member nation by September 30, 2024, 11:59 PM ET. Otherwise, this market will resolve to "No". The primary resolution source for this market will be information from the relevant EU member nation, however, a consensus of credible reporting will also be used.
The mechanism for this happening would be the EU Digital Services Act. It’s possible to apply to a court for suspension of service, which has a 14 day cooling period (and a lot of other steps, but that one is set in stone). So this is 0% before October already.
That ban was never enforced. The court removed it fairly immediately. It was obviously unworkable.