The article says they were already getting this information directly from the IRS until a court order shut it down. It is worthwhile to note that in the past the IRS stayed out of police investigations so that even if criminals were doing criminal things to make money, it didn't discourage them from paying taxes on it.

I would disagree with that premise, famously the FBI has used unpaid taxes to after a number of high profile criminals, most famously Al Capone but more frequently its gang members or fraud (like some of the Somali fraud cases in Minnesota). I believe they like to make your claim to encourage paying taxes, but practically they work together frequently. Crime shouldn't suddenly be ok if you pay taxes on it