The bit.ly approach might result in false positives as the namespace for bit.ly links is quite easy to iterate over (assuming you don't use a custom link). Als

The bit.ly approach might result in false positives as the namespace for bit.ly links is quite easy to iterate over (assuming you don't use a custom link). Also, doesn't bit.ly access a URL to pull a title or generate a preview? This would send a click through to the canary as well.