All our premium extras include regular license checks. This is where we send some data from your site (domain and stored license key) back to our server, and make sure that the domain is properly licensed. If we find an issue (for example, because you moved a development site to a live domain), we send you an email with a special link to resolve the license issue.
This system is what allows us to give you unlimited free development licenses on approved domains.
While the code was meant to be run once a week, it turns out that for ContentBlocks, SimpleCart, and Redactor, it had actually been set to run daily. This was discovered after Ben B reported several of his sites were slow loading ContentBlocks-powered resources the manager at the exact same time as ~2 minute server downtime happened on our end. This required rather specific timing (first login in over 24 hours, exactly while our system was unresponsive), and by reducing the times the license check runs we're reducing the chance of similar issues arising in the future by a lot.
Long story short, we've just released the following updates that set the license check to be weekly instead of daily: