As a matter of principle, disclosures on the internet form part of the state of the art according to Art. 54(2) EPC. Information disclosed on the internet or in online databases is considered to be publicly available as of the date the information was publicly posted.
According to the Guidelines, when an internet document is cited against an application or patent, the same facts are to be established as for any other piece of evidence. This evaluation is made according to the principle of "free evaluation of evidence". That means that each piece of evidence is given an appropriate weight according to its probative value, which is evaluated in view of the particular circumstances of each case (Guidelines G-IV, 7.5.2 – version 2012).
The EPO standard of proof is generally the "balance of probabilities" (see J 20/85, OJ 1987, 102). However, especially in cases where only one party had access to information about an alleged public prior use, the case law has tended toward expecting that the public prior use be proved beyond any reasonable doubt or "up to the hilt" (see e.g. T 55/01, and T 472/92, OJ 1998, 161) (see T 1553/06). The same strict standard was required for Internet disclosures in the decision in case T 1134/06 (affirmed in T 1875/06). Conversely, it has been laid down in both the EPO Guidelines and the "Notice from the European Patent Office concerning internet citations" that, in examination proceedings concerning Internet citations, the balance of probabilities will be used as the standard of proof for assessing the particular circumstances of a given case, and thus the probative value of the evidence in question. Proof beyond reasonable doubt ("up to the hilt") is not required (Guidelines G-IV, 7.5.2 – version 2012; see also "Notice from the European Patent Office concerning internet citations", OJ 8-9/2009, pages 456 - 462). In T 2339/09 the board of appeal applied he "balance of probabilities".
In T 2339/09, the board observed that information disclosed on the internet is considered publicly available from the date on which it was posted online. The board held that the balance of probabilities applied in deciding whether the prior art comprises the documents in question. According to the search report, D4 was an internet article dated 22 May 2006 and relating to a product catalogue of HBE GmbH, which had been found in an internet archive at www.archive.org on 21 March. The date of the catalogue's online publication was therefore 22 May 2006, i.e. before 17 November 2006, which was the filing date of the application in question. Moreover, the catalogue bore an imprint with the date "11.10.04", which suggested that it had been published "offline" even earlier. In any event, the relevant dates were prior to the filing date and it therefore had to be found that D4 formed part of the state of the art.
The board held that the appellant/applicant bore the burden of presenting the case for and proving the contrary, i.e. that D4 had not been published before the filing date. In the case at issue the appellant was unable to rebut the presumption that D4 formed part of the prior art.
In T 1134/06 the board found that a disclosure on the Internet could be comprised within the state of the art as defined by Art. 54(2) EPC 1973. If an Internet disclosure was to be used as prior art, a strict standard of proof should be adopted. Thus, the fact that an Internet disclosure formed part of the state of the art under Art. 54(2) EPC 1973 should be proved "beyond any reasonable doubt". The particular facts and evidence required would depend on each individual case, but would normally have to meet the criteria established by the jurisprudence of the boards of appeal in respect of a prior use or a prior oral disclosure, i.e. answer the questions of when the Internet disclosure was made available to the public, what was made available and under which circumstances it was made available to the public. Concerning the latter question, it would in most cases be necessary to address the main concern of reliability surrounding the Internet, in particular so as to establish whether, and to what extent, a retrieved disclosure was true to the disclosure appearing at that date.
The board went on to state that in certain cases, where a web site belonging to a reputable or trusted publisher published online electronic versions of paper publications, content and date could be taken at face value, and the need for supporting evidence could be dispensed with. It could also be envisaged that if a web site operated under recognised regulations and standards, which would allow the date and content of information retrieved therefrom to be established with a high degree of certainty, further evidence might also not or no longer be required. Of course, it should be clear for both the examiner and the public whether an Internet source was considered as "reputable" or "regulated". This again called for clearly defined guidelines. Where a disclosure had been retrieved from a resource such as the Internet Archive, further evidence concerning the history of the disclosure, whether and how it had been modified since the date it originally appeared on a web site would be necessary. This could be in the form of an authoritative statement from the archivist. Alternatively, an appropriate statement as to the content, either from the owner or author of the archived web site which included the disclosure could suffice.
In T 1875/06 the board fully agreed with this finding in decision T 1134/06 and applied the strict standard of proof to document (3), retrieved from the internet by the examining division when establishing the supplementary European search report. Document (3) was a printout of a web page. At the date of the decision, the URL indicated in the supplementary European search report did not permit retrieval of document (3) or of any other document. The board stated that, on the basis of the information provided, it would have been necessary to investigate further whether a document having the content of document (3) was available to the public before the priority date of the present application. The board decided that proof of the above assumption regarding the public availability of document (3) would depend on suitable further evidence. The board was therefore inclined to exercise its discretion under Art. 111(1) EPC and to remit the case to the examining division for further examination in order that it could carry out a further investigation to obtain the necessary evidence. In so far as a reasonable effort to obtain such further evidence was unsuccessful, the examination was to be carried out without considering document (3) as included in the state of the art.
In T 373/03 neither the author date of a PBS document recovered from the Internet nor its date of creation as found embedded in the code were accepted by the board as proving a date of availability before the relevant dates in question.
In both cases the information retrieved from the Internet was not excluded per se. However, both cases demonstrate the difficulties in determining the exact date of availability of such information (see T 1134/06).
In T 91/98 the board ruled that a date mentioned in the heading of an entry, which was retrieved from the Lexis-Nexis database (an Internet resource) much later than the relevant dates in question, could not be equated with the distribution date and, in particular, need not be right. Affidavits and declarations were also not found to establish the date of availability with the required degree of certainty.