The last.fm API is sometimes returning data for other users. This is a known issue in the last.fm API, and unfortunately we can’t do anything about it on our end. We’re monitoring the last.fm support forums while we wait for their team to fix the problem.
The latest update from last.fm in the support thread linked here is that they have released a fix, and haven’t seen any occurrences of this issue since. We’ll keep an eye out for it popping up again, but hopefully that’s the end of it.
