Motorolla Verizon Droid Internet Security Question?

[Behappy]

I've logged in Facebook through my phone many times and today when I try and log in it says "Security Warning. There are problems with the Security Certificate for this site. This certificate is not from a trusted authority." When I view the certificate it's Facebook Inc, so I have no idea what this means. Why can't I log into my facebook? It's working just fine on a regular computer