The Globe and Mail reports in its Tuesday edition that the U.S. Securities and Exchange Commission has collected thousands of staff messages from more than a dozen major investment companies, escalating its probe into Wall Street's use of private-messaging apps. A Reuters dispatch to The Globe says that previously, the SEC had asked the companies to internally review the messages in its investigation of Wall Street's use of WhatsApp, Signal and other unapproved messaging apps to discuss work. The two-year crackdown into potential breaches of record-keeping rules initially targeted broker-dealers, netting regulators over $2-billion (U.S.) in fines. The SEC's "off-channel" communication probe has expanded to investment advisers, marking an escalation of the investigation. "The more information you give the SEC, the more you fuel the beast," one source said. In the latest phase, the SEC has in recent months asked for messages on personal devices or applications during the first half of 2021 that discuss business. It has targeted a selection of employees, in some cases as many as a dozen, including senior executives. The firms include Carlyle Group, Apollo Global, KKR, TPG and Blackstone, as well as some hedge funds.