NEW YORK - US stocks dropped Monday on worries that Facebook's data breach scandal will lead to a regulatory crackdown on technology companies, while European bourses fell on lingering trade-war fears.

Major US indices shed more than 1 percent following reports that Cambridge Analytica, the data analysis firm hired by Donald Trump's 2016 presidential campaign, stole information from 50 million Facebook user profiles to help design software to predict and influence voters' choices.

• Trump consultants harvested data from 50 million Facebook users -reports

Facebook shares slumped 6.8 percent, but other tech giants such as Apple, Google-parent Alphabet and Netflix also stumbled on worries that additional scrutiny could result in regulations that crimp growth at many of the stock market's leading lights.

"What this has done has sparked a conversation that will probably affect quite a few of these tech names," said Shawn Cruz, manager for trader strategy at TD Ameritrade.

"If there's any sort of changes or regulation that comes out of this, it'll be applied across the board to all these companies that are using data."

The revelations will also lead to "a general increase in distrust among (Facebook's) massive amount of users," said Gorilla Trades strategist Ken Berman.

Market watchers said other events this week are also encouraging investor caution, including a Federal Reserve monetary policy decision on Wednesday and a G20 meeting of finance ministers in Argentina that could bring to the surface rising tensions on international trade.

Unease over trade dragged bourses in Paris and Frankfurt down more than one percent, analysts said.

"Concerns over the potential for a Trump trade war still seem to be weighing on the minds of investors, with a lack of risk appetite still leading to caution in global stock markets," FXTM research analyst Lukman Otunuga said.

Trump's tariffs on steel and aluminum imports worldwide are to come into effect on March 23, with the exceptions so far of Canada and Mexico, which have won temporary exemptions from the US.

The British pound rallied after Britain and the EU reached a landmark deal on a two-year transition after Brexit that will buy businesses and citizens time to adjust to life after the divorce. However, the parties still have not resolved the thorny issue of the future of the Irish border.

The strong pound weighed on London's benchmark FTSE 100, which shed 1.7 percent.

KEY FIGURES AROUND 5 A.M.

New York - Dow: DOWN 1.4 percent at 24,610.91 (close)

New York - S&P 500: DOWN 1.4 percent at 2,712.92 (close)

New York - Nasdaq: DOWN 1.8 percent at 7,344.24 (close)

London - FTSE 100: DOWN 1.7 percent at 7,042.93 (close)

Frankfurt - DAX 30: DOWN 1.4 percent at 12,217.02 (close)

Paris - CAC 40: DOWN 1.1 percent at 5,222.84 (close)

EURO STOXX 50: DOWN 1.2 percent at 3,394.79 (close)

Tokyo - Nikkei 225: DOWN 0.9 percent at 21,480.90 (close)

Hong Kong - Hang Seng: FLAT at 31,513.76 (close)

Euro/dollar: UP at $1.2339 from $1.2290 at 2200 GMT Friday

Pound/dollar: UP at $1.4026 from $1.3942

Dollar/yen: UP at 106.10 yen from 106.01 yen

Oil - Brent North Sea: DOWN 16 cents at $66.05 per barrel

Oil - West Texas Intermediate: DOWN 28 cents at $62.06 per barrel