From the New York Times
But after four years of studies, hearings and round tables, the Securities and Exchange Commission late last month abandoned efforts to impose new regulations on money market funds intended to prevent another panic like the one that occurred in 2008
About the safety of money market funds, the article had this to say:
In reality, this has always been an illusion, or what Ms. Schapiro calls a “fiction.”
how the Reserve Fund lost money in 2008. However, that wasn't the worst of it. From the article:
The Reserve Fund froze its assets and no one could get their money out, even though the actual net asset value was only a few cents less than $1.
Don't forget that a money market account is a bank deposit account. It should not be confused with a money market fund.