I wonder how feasible a business model it is to collect all the data from all leaks which make their way to the internet, massage the data a little bit, and sell it as a brand new "hack" of some popular service. You can probably do this a few times a year without a problem.
Why fake a new data leak at all? It's likely to be illegal either way. Depending on the quality of your work I suspect it would be easy to find buyers for aggregated and cross validated data sets on the black market.
For that matter, I have to assume that the shadier businesses silently make use of publicly available leaks. The data is just too valuable to ignore depending on your business model.
