Google launched the Web History feature a few months back.
It caught me by surprise as for at least a few hours I was over the moon thinking my keywords were all on 1 position. The sceptic in me started to investigate and this joy was short-lived ?
Since then every time I see an unexpected rise in the SERPS I go and check the web history feature. The blighter keeps getting switched on itself and it has now become a pain in the back side having to switch it off every so often.
Looks like I will have to find some sort of plug-in which will keep it switched off for good.