I noticed recently that I had lost about 20,000 listens and found this recent post on the listenbrainz blog regarding moving to a new database:
We also got rid of some bad data (timestamp 0 listens) that were pretty much useless and were cluttering the data.
For myself (and I assume many others) these timestamp 0 listens were from one off imports of local media player playcounts (only from winamp and itunes as I recall) that were permitted on last.fm when first opening an account.
Could I humbly request that this decision be reconsidered?