DHS’s IG says it’s probing the department’s practice of tracking Americans via the purchase of brokered cellphone data, after a letter from Democratic senators (Byron Tau/Wall Street Journal)

Salesforce announces it’s buying Slack in a $27.7B deal  —  Salesforce, the CRM powerhouse that recently surpassed $20 billion in annual revenue, announced today it is wading deeper into enterprise social by acquiring Slack in a $27.7 billion megadeal.  —  Every worker at every company needs …