I'm posting this here in order to draw this incident to the attention of the AP community.


Daniel Stenberg, the author of curl, a popular portable open-source file-transfer tool and library, is being consulted on a possible infringement of a mechanism for resuming interrupted file transfers. His blog has details, including already a substantial list of prior art which should hopefully be sufficient to overthrow the patent. Still, it would be useful to scrutinize the patent and at least verify his findings.

The blog is from 2011 and I am not sure what the present status of the litigation is. I was unable to find any further information by googling the case number. Has the case been dismissed? Or decided?

2 Answers 2


This particular case was is listed as Closed in Posttrial as of January 3, 2013.
It appears as though each of the defendants settled out of court.

One source for finding information on patent litigation is RPX, and information on this particular case can be found here.

You can create a free account to access all the information, including the docket entries.

In the initial complaint, the plaintiff, Content Delivery Solutions, LLC claims to be the exclusive licensee of the patents in question. This company is tagged by RPX as a non-practicing entity (i.e. patent troll).

Edit: After a little more digging, it appears that Content Delivery Solutions, LLC, is a wholly owned subsidiary of Acacia Research Group LLC, which is a wholly owned subsidiary of Acacia Research Corporation. Content Delivery Solutions admits to never deriving any revenue from selling software, not generating revenue since its formation and that its sole business is the monetization and licensing of patents1,2.


According to USPTO PAIR, patent 6,098,180 (application 08/804,114), "ROBUST DELIVERY SYSTEM", is listed as "patented case". Fees appear to have been paid, and the patent therefore appears to be in force.

The corresponding European Patent application (publication number EP1026866), "Robust File Transfer System", has been withdrawn following a negative search report.

Concerning the "patent troll" allegation in the question title, I am not sure I can agree. The patent was filed by Kobata and Tonchev of ATABOK Inc. (also known as e-parcel), a former division of Mitsubishi Electric, which is described as "provid[ing] secure file transfer services to the corporations in the United States and internationally". See: http://investing.businessweek.com/research/stocks/private/snapshot.asp?privcapId=3043964

Also note that the patent was granted in 2000, with a priority date of 1997, and not in 2011 as implied by the OP.

It should also be noted that for those reasons, the patent should only be valid for another two years, until 2017, at the most.

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