Hard to say whether Googlebot's following these "WebResult"-containing URIs from somewhere or causing them. They're huge -- the two I've been hit with were 558 and 466 characters long. Here's how they begin:
They include different dates and different content from who knows where, all separated by ASCII and who knows what.
I found mention of the same messes here: [google.co.uk...] (Note: The error generated is not the important part, the matching URIs are.) I reckon it's easier for you to see what they've posted than to slog through my including strikingly similar, huge URIs.
And here's a description of the 'decoded' URIs from that thread. It's akin to what I'm seeing:
It appears to be based on a malformed XML with elements <web:Results>, <web:Title>, <web:Description>, and <web:URL> that should end between these two elements </web:WebResult><web:WebResult> and contains information on at least two different sites.
Yep. Yep. The structure's identical but the parts differ. And the two sites included in each URI share a word but aren't otherwise related, like apple and appleaday.
Ultimately, that thread's so-called 'helper' summary --
I see any more time spent on this issue as purely an academic exercise.
-- struck me as a rude, 'It's all in your head' excuse for admitting: "I don't know."
Anyway. Anyone else seeing massive "WebResult" URIs all of a sudden? They almost look like Googlebot's scraped someone else's search results, or is barfing parts of its own indices. Beats me.