I mentioned a few days ago a Times article quoting CRU scientists that they had lost much of the raw temperature data upon which their house of cards is based. I received an email full of foul language and personal insults calling me a liar, and pointing to this. (I expect foul language and rage from environmentalists. They seem to have trouble remaining calm.)
It turns out that while CRU discarded some of the raw data, it is claimed that the original data is still out there:
[Response: No. The original data is curated at the met services where it originated. - gavin]What this means is that with a bit of effort (probably a lot of effort), you could request all of the raw data from the various national meteorological services and reconstruct what CRU started from. But without a comprehensive list of what datasets were originally in CRU's raw data, you wouldn't get the same results. The problem of inability to recreate the massaged data because of discrepancies and deficiencies in the programs mentioned in the HARRY_READ_ME.txt file, of course, would be an issue.
UPDATE: It may not help to ask for the raw data, unless you do it behind their backs. Lord Monckton's report (starting at p. 31) points out that New Zealand's government published data showing rising temperatures over the last century--but when some troublemaker actually downloaded the data from their website, it turned out that the rising temperatures weren't in the raw data at all. The New Zealand government had "adjusted" the raw data before producing their own claims, and refuses to explain the rationale for the adjustments.