If it's suddenly disappeared, suspect foul play.
Sigaint, one of the largest dark web email providers, is approaching its third week of unavailability with still no clear signs about what's happening to the service. The site has been down since at least February 11, with no news about what's happening as yet. In the absence of a clear explanation, speculation is, …
Shouldn't federal agencies be serving the public interest? Anonymous email is incidental to the public interest so there's no reason for it to be outlawed, attacked or shut down. The public should have a right to know what's being done in their interest by those entrusted with authority and funded by our taxes.
AFAIK no one actually knows why this service is down. Could be a perfectly innocent reason, such as running out of money, broken server they can't afford to replace, all sorts.
I dunno about the USA, but in the UK conversations with one's Member of Parliament are privileged. You can go to their office and talk about anything, and no one can force them to reveal their source when they raise the issue elsewhere on your behalf.
Society doesn't need electronic anonymity to function properly, it simply requires people who care about something important to get off their backsides and actually go see their MP. And if they can't be bothered to do that then one wonders whether the issue they're concerned about is really that important.
I would be surprised if conversations with one's senator or representative weren't similarly protected in the USA.