The recent high-profile example is a far-right group conspiring to kill the governor of Saxony.

https://www.npr.org/sections/coronavirus-live-updates/2021/1...

Very sad. The truth is everyone who wants to get vaccinated has got the jab already. Time to stop doubling down on mandates and remember we're all humans.

Someone I know is a physician at a hospital. She looked awfully tired when I met her a few days ago. "Too much corona", she explained. Shall I just suggest to her that it's time to stop doubling down?

There are two variants:

People running what amounts to blogs on Telegram, and reaching a wide audience. Nominally they're groups but only one person can post. They can run ordinary blogs on the web and not get many readers, they can post on Facebook but the moderation there is said to be effective now. Telegram provides them with a large audience and no moderation. https://en.wikipedia.org/wiki/Attila_Hildmann

Nazis looking for groups where they can recruit. The cliché is a group set up to organise protest against e.g. some new gravel pit in what was a quiet little forest, where a couple of nazis join and then mention that this gravel pit is really just another example of how capitalist jew pigs grow rich at the expense of ordinary people like the neighbours of that gravel pit. It's not clear to me why Telegram works better for them than Facebook groups. Perhaps a question of moderation style.