A more thorough explanation:

A blackmail suit is a type of lawsuit filed by a party who has no genuine claim but hopes to extract a favorable settlement from the defendant who would rather avoid the expense and inconvenience of litigation. It is often used as a tactic to extort money from the defendant.

• A person files a lawsuit against a company claiming that they were injured on their property, even though they were never actually on the property. The person hopes that the company will settle the case to avoid the cost of going to court.
• A former employee threatens to file a lawsuit against their former employer for discrimination, even though there is no evidence to support the claim. The employee hopes that the employer will settle the case to avoid negative publicity.

These examples illustrate how a blackmail suit can be used as a tactic to extract a settlement from a defendant without having a genuine claim.