Notify users when a title is removed from Letterboxd
Letterboxd needs to implement an automated system that can notify users when a film they have watched, logged or added to a list is removed from the website.
Sometimes, titles are removed from Letterboxd only to be added back, such as the 'Kenzo World' commercial. If I remember correctly, several hundred viewers had logged the ad when it first released on YouTube, including myself. It was only when I downloaded my Letterboxd archive that I noticed the film's URL field in the .csv file was empty, meaning it had probably been removed from Letterboxd at some point and was no longer in my profile. I then searched for it on the site, and found the title was actually still on Letterboxd, but now with only very few people who had marked it as watched. It's possible that the second 'Kenzo World' title was an entirely different entity, but notifying users that a title they have watched has been removed allows them to appeal against its removal or make a note of it so they can keep an eye out for its return in the future. If you are feeling extra generous, you could even create a private page that shows a user all the titles they have watched that are no longer on the site, and provide a link to their TMDb pages :-)
The same goes for users who create large, comprehensive lists on the site. If any title is removed from Letterboxd, many list creators have to cross-check the entire list to find the missing title, like LB user Jayce Fryman had to do with his 'TSPDT Starting List'.
I think this would be a very useful notification feature to have that users can opt in for as Letterboxd continues to grow, so I hope you will consider it.