What is the phenomenon called when multiple sites appear in a web browser in just a few seconds from clicking on a single link?

The phenomenon where multiple sites open in a web browser almost simultaneously after clicking on a single link is known as a "popup bomb." This occurs when a single action triggers numerous pop-up windows or tabs, often overwhelming the user. Popup bombs are frequently used as a form of annoyance tactic in browser exploitation and can slow down or crash systems due to excessive resource consumption.

Understanding popup bombs is important in the context of web security and user experience. Users should be aware of how some websites, particularly those with malicious intentions, may implement such behaviors to disrupt browsing or lead to potential security risks.

The other choices represent different concepts: recalcitrance generally refers to resistance to authority or control, a rootkit is a type of malicious software designed to grant unauthorized access while hiding itself, and URL harvesting involves gathering URLs or web addresses from a source, typically for spamming or malicious purposes. None of these terms relate to the immediate opening of multiple browser windows or tabs as a result of a single action, confirming the uniqueness of the popup bomb phenomenon.