An action for groundless threats is provided for any person aggrieved by unjustified threats of infringement proceedings under section 53.  This right to take an action was however restricted under the original section, if the “threats” in question mentioned only the manufacture or the importation of the patented product or the use of the patented process.

The intention of this restriction was to limit the use of unjustified threats actions to secondary infringers, namely those who merely sold an infringing product without having made or imported it, or those who bought the infringing product and subsequently used it. The philosophy underlying this restriction is that while a patentee can prevent such secondary infringements if ultimately successful in court, some means should exist to restrain patentees from making unjustified threats against those who know nothing about the manufacture or importation of an allegedly infringing product.

There was a loophole in the original wording, however. If a patentee correctly identified the primary infringer, but worded the letter so that it included mention of the sale of a product (as well as its manufacture/importation), the primary infringer could initiate a court action for unjustified threats merely on account of this mention of the product's sale.

New wording has been introduced to exclude any action from being taken regarding: "a threat, made to a person who made or imported a product for disposal or used a process, to bring proceedings for an infringement alleged to consist of doing anything else in relation to that product or process".  In other words, if the party against whom the threat was made is a primary infringer, they no longer have recourse to the threats action, irrespective of the wording of the letter.