That's not big brother at all, that's someone abusing a position of trust; and in the US, not here If you're going to bang on about big brother stuff, at least a) pick something germane and b) in the UK.
which is that this woman was able to access all kinds of personal information, including mobile phone and email accounts, using an ordinary US government desktop computer.
She worked for a laboratory that's owned by The US department of energy's National Nuclear Security Administration, and over a fairly long period she monitored her victim's email. This enabled her to get all kinds of information, including passwords for various accounts - including the mobile phone accounts.
If nothing else, this is a salutory warning to people who might think that private emails are absolutely private. That's not necessarily the case, as this woman chillingly demonstrated.