Just to be clear, the previous comment has nothing to do with the recent story!
@DefenceTelegram648

Again, writing "i will kill xx" can be done EVERYWHERE!
@GazaHamasTelegram63
@GazaHamasTelegram73

and previous terror attack were announced NOT on Telegram, but other social medias.

You can announce everything EVERYWHERE! means:
Discord
Your house door
Calling the police
Writing the government (yes, a terrorist wrote them and THEY IGNORED HIM!, like Norway ignored multiple terrorism behaviours done by Breivik BEFORE the massacre!)
Messengers, like Signal, Threema, WhatsApp, etc.
YouTute
TikTok
Instagram
Pinterest
Russian, Chinese or other socials
Reddit
Vimeo
Twitter
Mastodon
etc.

So it doesn't matter! Like people shared livestreaming of rape, suicide, terror attack or other crimes / things on such socials!