Yesterday and this morning I couldn't long into my Bonvoy account. When I tried to reset my password I learned that someone had changed my email address. When I resolved that issue and reset my password I looked at my account activity to find that on 4/3/19 (yesteday), someone hacked into my account and used 400,000 points! This included buying flights on United Airlines, which I don't even fly! The customer service agent that I spoke to said that someone would be in touch but she could't say when. This was far from reassuring.
I'm surprised at the hacking because usually any account changes generates a text or email to confirm. I received neither.
I've been loyal to Marriott for 23 years and have Lifetime Titanium Elite status.