Dailycaller has some info on legality:
http://dailycaller.com/2017/02/02/epa-employees-are-using-encryption-technology-to-hide-resistance-to-trump-but-is-it-legal/
But is it ‘work related’ to oppose the Department on one’s own time and devices?
Obviously not! It’s Firt Amendment!
However the info in the messages may be illegal for other reasons: confidentiality rules. So encrypt it.
Encryption is a much more difficult problem than people realize.
Thanks for adding that link and your comments. These traitors are following Hitlery’s precedent and consider themselves immune to prosecution.