Which of the following was not identified as a form of invasion of privacy?

Invasion of privacy typically involves actions that violate an individual’s right to keep their personal information and activities private. Hacking, surveillance, and data mining are all activities that intrude on someone's privacy by accessing or gathering information without consent. Hacking refers to unauthorized access to someone's digital devices or accounts, surveillance involves monitoring someone's activities without their knowledge, and data mining involves analyzing large sets of personal data to extract information about individuals, often without their permission.

Trolling, on the other hand, while disruptive and often harmful in an online context, does not inherently involve the unauthorized access to or invasion of someone's private information. Trolling is more related to provocative behavior and instigating reactions from others, rather than an invasion of privacy in the legal or ethical sense. Therefore, it is categorized differently and does not fit within the established forms of invasion of privacy like the other options do. This distinction is what makes trolling the correct answer in this context.