The years and years of Microsoft polluting web logs with fake referrer data, which they have ‘fixed’ numerous times, including a couple weeks ago.

We had confirmed reports from webmasters that Bing was no longer showing up in the log files with fake referrers. But I am seeing a new report that the log files are showing Microsoft Bing IP addresses in them but without referrer data.

An updated Bing Forum thread has one webmaster explaining the situation:

So this does not generate fake keyword referrer data, but it does spike up Bing’s referrer traffic for specific pages. That is assuming the webmaster who posted this is correct.

Forum discussion at Bing Forum.