I thought to update the limits to avoid spam.
On my site, it is very often the users reach the limit of posts or votes per hour.
How do I know if a plugin has used cronjob?
I installed plugin Best user per month in one day, but already uninstalled.
Plugins of my site:
Facebook Like Box
My followers page
On site notifications
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I did not programmed any cronjob.
But I've had other plugins.