(Read more: And so they go: SAC loses two more star traders)
As part of a $1.2 billion settlement with the Justice Department last year over accusations that the firm tolerated and even encouraged improper trading, SAC has returned nearly all its public investment capital and laid the groundwork to become a so-called family office, managing between $9 billion and $10 billion belonging to its founder, Steve Cohen, and select relatives and employees.
The new company, whose prominent stock-investing arm has been renamed Point72, will officially open April 7—even as the trading firm awaits a judge's final approval of the settlement agreement.
What SAC's roughly 850 employees will make of the enhanced monitoring programs is not yet clear. So far this year, about a half-dozen investment management employees have left the firm, a rate of turnover the company describes as well in line with that of prior years.
(Read more: Battered SAC Capital morphs into Point72)
But knowing that their phones, computers and other communication devices may be heavily scrutinized by the firm may come as a turnoff to workers already feeling pressured by the negative publicity surrounding their employer.
Of course, that surveillance is already underway. As part of a pilot program first discussed nine months ago, Conheeney wrote, Palantir was able to "embed" with SAC's compliance team and run a temporary monitoring project. That pilot was a "success," the firm president added, leading to the data miner's hiring.
(Read more: These six investors made $1B-plus last year)
Palantir, which generates revenue of some $500 million, has a blue-chip history both in the tech business and on Wall Street.
Capitalized by investors like Peter Thiel, the PayPal co-founder, the revered former hedge fund manager Stanley Druckenmiller and the In-Q-Tel venture fund run by the CIA, its past clients have included JPMorgan Chase, Morgan Stanley and the Defense Department.
—By CNBC's Kate Kelly. Follow her on Twitter