Due to triple damage provisions of patent law, for knowingly violating a patent, many companies bar engineers from visiting the USPTO site or looking at any patents. Do these sites which help with online patent searches also pose a similar risk for engineers?
There are lots of potential benefits for engineers who understand patent law and who take some time to understand what competitors are trying to protect. However, the question focused on problems associated with using this site.
Two potential legal problems are (1) being charged with willful infringement (or inducing infringement); and (2) beign charged with inequitable conduct. It is my view that neither of these are likely although some precautions might be needed to ensure that you do not run into trouble.
Willful Infringement: Patent infringement is often thought of as a strict liability tort. It does not matter whether you intended to infringe or even knew that a patent system exists. Rather, if you are practicing someone else's patented invention then you are an infringer. Knowledge and intent come in a few ways. First, if a jury knows that you might have copied then they may be more likely to judge you as an infringer (even though copying is irrelevant to the law on that issue). Second, once you are judged to be an infringer the court can treble (triple) the damages if the infringement was "willful." Knowledge of the patent is a critical element of proving infringement. Third, sometimes parties are sued for inducing infringement -- i.e., encouraging someone else to infringe. If you are liable for inducement then you will be jointly liable with the actual infringer. Inducement requires proof that you knew of the patent and encouraged someone to infringe it.
Now, in this discussion of infringement, I have been using the pronoun "you." The question was about engineers, and engineers are almost never accused of patent infringement. Rather, it is some company that they work for who is accused. Usually, the knowledge of a single engineer will not be imputed onto the company itself. That changes if the engineer is somehow in management or if the information is shared with the group.
The way to protect against willful infringement is not to bury your head in the sand. Instead, when you identify a patent that your company may be infringing, you should identify the patent and notify your counsel. In most cases the attorneys will be able to provide a fairly simple course of action that avoids the threat of treble damages. In any event, the trebling of damages is normally 5-10 years down the line if ever.
Inequitable Conduct: I suspect that many of the engineers looking at this site are involved with obtaining their own patents or are perhaps leading their company's patent efforts. Anyone involved with the filing of patent applications (including the inventors) owes a legal duty of candor to the USPTO. In addition to telling the truth, this duty also requires that you inform the USPTO of any information that you have that is somehow material to the prosecution of the patent. Most often, this obligation is satisfied by submitting copies of all the relevant prior art that you know about to the USPTO. The average patent applicant submits about 10 documents of this type to the USPTO per patent application. Besides the duty of candor, it turns out to be a good thing to submit prior art to the USPTO. Every quantitative study that I've seen on the topic finds that patents tend to be more valuable when more prior art is cited by the applicant. This shows the world that you care about the invention.
Now, the USPTO usually does not catch anyone failing the duty of candor. Where it comes up is later in litigation when you are trying to save your company by enforcing the patent. If it turns out that you failed to submit important material, the patent can be held unenforceable. The best course of action here is very straighforward - when you see information on this site that is somewhat close to a patent you are working on, then you should submit that information to the USPTO - easy.
Treble damages are awarded on a discretionary basis by the judge in the case, however, enhanced damages are only applicable in cases of willful infringement. The judge determines as a matter of law what is willful infringement by using a two-prong test:
(1) "that the infringer acted despite an objectively high likelihood that its actions constituted infringement of a valid patent" and
(2) that the infringer had knowledge (or should have known) of this risk.
So the risk to engineers for using this site seems low. A judge would have to make the determination that the engineer in question derived information from here that somehow aided in a separate determination that the engineer had an "objectively high likelihood that its actions constituted infringement of a valid patent," and "had knowledge (or should have known) of this risk."
That is a long string of "what ifs" to connect.
Recommended Further Reading:
Rumour has it that triple damages aren't guaranteed, but a judge can decide whether to award them or not. Just because an engineer looks at this site doesn't mean that (a) he understands what he is reading, (b) realises it applies to what he is working on or (c) realises it applies to another teams work within the same organisation.
As others have commented on HN, not looking is sidestepping the issue. If you aren't looking, you are neglecting any genuine patent holders their right to recognition for their work. If it's a dodgy patent, you should - in an ideal world - destroy it in court anyway.
Just staring at USPTO site doesn't indicate known patent infringement. However when a patent infringement lawsuit is filed the plaintiff can apply for gathering evidence from the proposed violator.
Evidence requested will definitely include all corporate email (that's for sure) and likely can include logs of the corporate proxy servers and firewalls (not sure, but it's likely possible). The email may contain employees discussing patent search results (like "Joe, I've searched whether this thing was patented and...") and logs may contain URLs requested which can make it clear that a patent search was done for certain keywords.
So yes, leaving traces of a patent search in any form such that they can be discovered and brought to the court may pose a problem.
I used to work for a very large and well-known company as an 'engineer', and filed a handful of patents there in the field of electronics and display screens. I think we outsourced the 'legalese' drafting of the patents to qualified people - who also performed basic Prior Art searches for us. They might come back with 30-odd possible 'prior-arts'; typically the vast majority of these could immediately be dismissed and 2-3 would need looking at closely. Sometimes you'd just have to admit one of those was exactly the idea you'd hand and drop the case there and then. Otherwise you might still have to look carefully to draw out the differences between your idea and the prior art - and maybe narrow your own patent to avoid coverage of the existing one.
Given the scatter of hits that typically came back from their searches, I suspect that sometimes they likely missed some relevant prior art - but I don't know what you can do about that. Big companies play all sorts of games with patents - including giving them highly generic titles, which does not aid finding them in searches. :-(