The biggest problem with downdetector is how they visualise their outage graphs.

The Y axes are entirely independent, and so when there's an outage for Microsoft Outlook (which peaked at ~130k reports) and you get a negligable spike in pepole who get confused and report gmail (~1k reports), the graphs all look correlated and connected.

They need to show the graphs with an absolute y-axis set by the worst outage, or scale the graphs by estimated average daily users or something.