Sally has been working really hard lately and asks her manager for a raise. Her manager tells her that she is already the highest paid employee on the floor. Sally doesn't believe her manager, and illegally accesses the employee database to look at salary data. Sally's act can be termed as

Sally's act is termed as hacking.

Explanation:

As Sally has accessed the database and used illegal means, this is termed as hacking. As per the Merriam Webster definition of hacking, hacking is the act of gaining illegal access to (a computer network, system, etc.).

Thus the definition of hacking is applicable to Sally's act here.