It is a general principle that, when raising objections, the burden of proof lies initially with the examiner. This means that objections must be reasoned and substantiated, and must show that, on the balance of probabilities, the objection is well-founded. If this is done, it is then up to the applicant to prove otherwise - the burden of proof shifts to the applicant.
If an applicant provides reasons for questioning the alleged publication date of an internet disclosure, the examiner will have to take these reasons into account. If the examiner is no longer convinced that the disclosure forms part of the state of the art, he will either have to present further evidence to maintain the disputed publication date or will not use this disclosure further as prior art against the application.
The later the examiner sets out to obtain such evidence, the more difficult it may become. The examiner should use his judgment to decide whether it is worth spending a short amount of time at the search stage to find further evidence in support of the publication date.
If an applicant refutes the publication date of an internet disclosure with no reasoning or merely with generic statements about the reliability of internet disclosures, this argument will be given minimal weight and is therefore unlikely to sway the examiner's opinion.
While the dates and content of internet disclosures can be taken at face value, there are of course differing degrees of reliability. The more reliable a disclosure, the harder it will be for the applicant to prove that it is incorrect. The following sections look at the reliability of various popular types of internet disclosure.