> 2. A startup that was acquired by a larger company and the acquirer is trying to protect its shiny new purchase

In particular, it seems far too common for a patent troll to see a company that just got funded or acquired and figure they can extort some of the new funding. So it makes perfect sense for a newly acquired or invested-in company to spend some of the new funding they just got to set up a small stack of defensive patents or publications.

That said, for both of those cases it would potentially be cheaper and equally effective to file defensive publications rather than patents.

Do you mean a Statutory Invention Registration[1]? That seems almost as troublesome as putting together a regular application, just without some of the followthrough. Or is there actually a solid way to establish prior art just by publishing your method? I've been wondering if there's some threshold of "publication legitimacy" that's required for this, or if posting the method up on pastebin would work. I found a piece on how to establish prior invention for business methods[2], but that only protects the folks that can document their own prior use.

[1] https://en.wikipedia.org/wiki/United_States_Statutory_Invent... [2] http://www.fenwick.com/fenwickdocuments/new_defense.pdf

There is a service [1] that does this, and is registered as a "mandatory to search" resource with the WIPO. It costs $120/page, which is steep, but surely cheaper than patent prosecution. There are other "mandatory search" archives [2] under the Patent Cooperation Treaty "Minimum Documentation" rules, many of which are academic journals. These are not the only means of "public disclosure" but my (very limited) understanding is that the patent office is guaranteed to look at the sources on that list.

[1] http://www.researchdisclosure.com/publishing-disclosures

[2] http://www.wipo.int/standards/en/part_04.html

>"the patent office is guaranteed to look at the sources on that list"

The PCT minimum documentation is what must be available. The examiner will have to balance time and costs (databases of journals can be costly to interrogate) against their considerations of what material it would be useful to search.

In the UK the examiners used to keep up with journals appropriate to their field - so publishing an article in a trade journal or maker magazine about 3D printing would be a reasonable place for disclosure in this case.

There's another option for those familiar with the patent system - pick a country with low fees and file an application, get an A-publication and abandon the application. In the UK that will cost £30 (~$50) on application plus £150 for the search (you can file both online and get £30 off). It doesn't matter how big your application is; you don't get charged more for a 1000 page application than you do for a single page. It won't get refused until after publication even if it's absolute nonsense. It can however take a couple of years but you can reduce that to about 5 months by getting an accelerated search.

Aside: Theoretically you could break the UKIPO by submitting an application that's millions of pages long. Under R48(1) the UK office has to provide copies to anyone on request for a fee of £5 (with a Form23). There doesn't appear to be a restriction on the address either, anywhere in the European Economic Area is fine. However there's also a rule that requires one to provide, or pay, for 3 paper copies of an application to be made IIRC.