The phrase "a troubling example of" is correct and usable in written English.
It can be used to describe a situation, event, or phenomenon that raises concern or discomfort, often in a critical context.
Example: "The recent data breach is a troubling example of how vulnerable our personal information can be."
Alternatives: "a concerning instance of" or "a disturbing case of".
The case of the geologist, Xue Feng, is considered a troubling example of China's rough and arbitrary justice system.
He called the catfish war "a troubling example of the very protectionism we have urged the Vietnamese to abandon".
In a statement, Clinton called the price hike "outrageous" a "troubling example" of pharmaceutical companies taking advantage of consumers.
A troubling example of fragmentation comes from dealers who match buy and sell orders from their own customers without directing them to floor exchanges, Nasdaq or anywhere else.
It's also a troubling example of how Donald Trump's wide ranging executive order to ramp up immigration enforcement may be giving federal immigration authorities a stronger foothold in America's schools.
Mr. McCain said the import restrictions had been slipped into the bill at the behest of "wealthy catfish growers" in the United States and were "a troubling example of the parochialism we have urged the Vietnamese government to abandon" in its trade policy.
Guinea is a particularly troubling example of the region's summer of trouble.
The most serious disruption of our economy in recent memory, the 2008 financial crash, is a particularly troubling example of this pattern.
As a specialist in African history teaching at an institution with a long standing study abroad program in Kenya, the nearly 20% decline in U.S. students studying in Sub-Saharan Africa offers a particularly troubling example of short sighted and reactionary policies.
And it's an awfully troubling example of Palin family values.
Here is a troubling example: While we were all busy with elections, the State Board of Elections issued a draft proposal for buying $220 million worth of new voting machines.
