What is Floodgates Principle?

Legal Definition
The floodgates principle, or the floodgates argument, is a legal principle which is sometimes applied by judges to restrict or limit the right to make claims for damages because of a concern that permitting a claimant to recover in such situations might open the metaphorical "floodgates" to large numbers of claims and lawsuits. The principle is most frequently cited in common law jurisdictions, and in English tort law in particular.

Most of the situations in which the courts have employed the floodgates argument have revolved around liability in tort, and in particular in relation to the liability for nervous shock or for pure economic loss. The rationale in which the floodgates principle has been applied may vary. In some cases it is expressed to be a constraint upon when a defendant will owe a duty of care, in others it is expressed to be a limitation upon the remoteness of damage for which a defendant should be held responsible for.

The floodgates principle is arguably the antithesis of the legal maxim: fiat justitia ruat caelum ("let justice be done though the heavens fall").
-- Wikipedia