Connection is Untrusted - Invalid Security Certificate - Expired - Facebook,Google... Https

Hi,
Today seems that something's doesn't want run in Secure Connection via Https in many Sites... like Facebook.com , Youtube.com & Google.it.
This happens with Mozilla Firefox that analyze those conditions...
Or It's a fake message?
Anyway the Cetificate seems to be expired...
Anyone can tell Us about this? ;)



www.facebook.com uses an invalid security certificate.

The certificate will not be valid until 21/06/2012 02:00. The current time is 12/03/2012 09:50.

(Error code: sec_error_expired_certificate)



accounts.youtube.com uses an invalid security certificate.

The certificate will not be valid until 27/06/2012 15:58. The current time is 12/03/2012 09:14.

(Error code: sec_error_expired_certificate)



accounts.google.it uses an invalid security certificate.

The certificate will not be valid until 27/06/2012 16:03. The current time is 12/03/2012 09:36.

(Error code: sec_error_expired_certificate)



Thanks :)