Zero tolerance is a hardline policy preventing or protecting against something that is undesirable in a given environment. In a human resources context, for example, a zero-tolerance policy might stipulate that an employee who bullied another staff member would be fired rather than reprimanded, temporarily suspended or required to attend corrective training.
A few more examples of zero tolerance:
Deplatforming is the practice of removing someone’s access to channels for delivering their content to an audience. The term is often used in reference to terminating users’ social media accounts. In such cases, terms of service (ToS) may indicate zero tolerance for particular behavior, such as trolling.
Air-gapping can be considered a zero-tolerance approach to network traffic. Air-gapped systems are, at least in theory, protected from access from any external source.
Contracts between partners often stipulate zero tolerance for violation of agreed-upon terms, and some violations may render the contract null.
Businesses that rely on IT infrastructures to conduct corporate operations may have zero tolerance for network downtime.
Although there are situations where zero tolerance is advisable or even necessary, critics of such hardline policies argue that, among other things, they may lead to premature judgments and deprive individuals involved of their rights to due process.