which information security characteristic(s) violated (or of some combination of characteristics)

Q1. Sara's login information to an online shopping website is discovered by Maher. He logged into the system using Saras ID/password, and made a purchase using her saved visa card

-confidentiality

-integrity

-availability

-authenticity

Q2. Sara's login information to an online shopping website is discovered by Maher He updated Sara's ID/password and personal information

confidentialit -

Integrity

-availability

-authenticity

Q3. Eve installs firesheep and hijacks Alices Facebook session. She reads Bobs messages to Alice and sends a response.

-confidentiality

-integrity

-availability

-authenticity