“Back when I was young,” all we had to do to file an infringement suit was use Form 18 and basically allege “Plaintiff owns a patent and you sell stuff that infringes it.” (For one story about the process of repealing it (and almost all of the forms that used to be sufficient as a matter of law to state a claim), read here.) Abolishing the form meant that the Iqbal/Twombly requirements of pleading factual material, not naked allegations or legal conclusions, which if true plausibly showed infringement.
That eliminated the ability to sue for infringing some patents — say a method claim practiced inside a factory.
At the same time Form 18 went away, the scope of discovery was narrowed. While everyone focuses on the proportionality requirement, Rule 26 was also narrowed to eliminate the ability of a court, even for good cause, to permit discovery into the subject matter of a suit — only discovery into claims or defenses was permitted, and it had to be proportional and so on.
So, that again eliminated the ability to sue for some infringement, and it made it very important that pre-suit investigation identify every infringing product/use possible, or at least do so early and consistent with patent local rules. This is because courts do not permit patentees to obtain discovery into products beyond those identified in a complaint, or early in infringement contentions, without showing reasons why the product was not identified through other means (e.g., Internet searches on the manufacturer’s web page).
A recent case shows this process. In Aavid Thermalloy LLC v. Cooler Master Co., (Case No. 17-cv-05363-JSW (LB) (May 10, 2018), the court denied the patentee’s request for discovery beyond products accused in its PICs, stating that the exception to the general rule that such discovery was not allowed was only available if the patentee did not “know of” the allegedly infringing product when it served its infringement contentions “and could not have discovered the product absent discovery.”
So, be careful in your pre-suit investigation, and be thorough. On a larger scale issue, this is but one more way that the value of patents have been reduced.