Hey to the marketing team of Nitrokey,
it would be great to see you on Mastodon, too. You are on Twitter and so on, but not on a real nice, open-source and federated alternative social network called Mastodon.
That seems to be a Diaspora instance. Also the link is a mail address and you cannot easily guess the URL, so I I cannot confirm it, but I doubt this is an official account.
Yeah, I should have probably said Fediverse. I would not recommend Diaspora right now though, as it does not support the ActivityPub protocol, the standardized protocol for such things.