In theory, the fruits of the poisonous tree law should only apply to narcotics detectives, not private detectives or anyone else. Basically, the law is this: if the police use an illegal act like an illegal arrest and search to gain evidence to convict a suspect of a crime, that evidence that resulted from the illegal act (the fruit of the poisonous tree) can’t be admitted at trial. The reason is obvious; if the fruits of the poisonous tree were used against you, then you couldn’t use them at a trial because the fruits were used against you, right? It’s a circular argument, doesn’t it?
Some may suggest: that if the fruits of the poisonous tree were used against you legally, then the defendant should have some sort of defense for using the fruits against you in the future. Perhaps the defendant could argue that he wasn’t trying to get more money from you, but that he didn’t want to sue you. Some jurisdictions do allow a defense under a wrongful death statute for someone dying from ingesting the plant. But in the end, it really comes down to a choice of all risks. Do you want to take a risk of having your life ruined, or do you want to take a risk and save your life?
In short, if a patented invention isn’t useful to anyone: it’s not a good idea to protect it with a patent. However, there are a couple of exceptions to the no-treat-and-hold doctrine. If the product has some value to others, such as to a parent who wants to give its infant something better than the product the infant was eating, then a patent might actually be warranted.
In addition, one may infringe a patent even if the product: that is being protected is completely new. The “good prior art” defense can be used if one can prove to a court that a prior art product is older than the one being protected and therefore infringes the patent. The difference between an infringer and an innocent infringer is that an infringer doesn’t need to prove that he didn’t create something new; he simply needs to prove that someone else did. And, while innocent infringers can still be held accountable for what they did, it depends on the details of the case, as to whether there was any secret technology, formula, or process that was protected by a patent.
One other point that often comes up in patent law: is whether a person can infringe a patent even though the product is clearly a continuation or development of what another person has come up with before. The short answer is no. First of all, even if the new product is technically substantially similar to what was already sold, it wouldn’t necessarily be considered an infringement. For instance, a person might confuse a new product that has an array of features, but is only able to perform two basic functions, with what is typically sold as a television. That being said, it is entirely possible for a person to construct a new item that is capable of performing two or more basic functions, but does not incorporate any of the improvements that are normally found in competing products.
Because the penalties associated with infringement: of patents can be quite high and can actually cause the loss of a company’s entire investment, it is important that an infringer’s product is discovered as soon as possible. However, in order to encourage the discovery of an infringing item, a company may use one of many specific incentives. For example, some companies offer money to customers who bring in a specific product as evidence that they saw the patented product in activity.
In addition, some companies provide their employees with a bonus for each successful product they identify; the more successful a patentee is at getting an injunction, the more money these companies gain from these incentives.