Uli, just noticed tonight that there is only myself and Fred on the forum as registered users, the other 45 or so are listed as guests and "unknown action" is this (Unknown action) an indication that they are spammers?
Well, I noticed this (unknown action) at times and before we closed the registry, it used to be when I'd deleted a long list of spammers it seemed to be that the person (or rather spambot, not a real person) was looking at the profile of a spammer - but as I'd deleted it, it didn't exist anymore, thus "unknown action". Now it seems those spambots are still following an old automatic link to a profile which does not exist anymore.
(However I'm sure a part of the guests are "real", just unregistered (or not logged in) and reading in the forum.)
"Unknown action" is what my wife gets up to when she says she's been busy all day!
Maybe - it might also be what I do when I "work" on the computer...