Fake bits pollute the supply chain, you can't tell what is good or bad.
Once upon a time, I worked for a long established british company that made .... Their products were very good, had been going for a long time, they created a lot of the main technology and manufacturing products used in medicine manufacture. They used one main OEM to build control boards. Unfortunately one of these boards would occasionally blow up, an LM358 opamp, specified as a Nat Semi part, would go short across the power lines, the design used a thermal limiting fuse, and when you pump 50W of power into a short circuit chip it cooks the PCB destroying it.
Trouble is the evidence is now destroyed. I strongly doubt the failed component was of National Semiconductor in origin, trouble is the pinning for this chip is commonly used, anyone could take any jelly bean opamp made by some crap far east company, relabel it as Nat Semi and the ISO9000 OEM would buy it cause it was cheap. Reputation got damaged, once a new £500,000 machine failed after 3 months. The word got around.
The company is no more, another death in british manufacturing ability, all because some sh*t OEM saved a few pence.
That is one of the consequences of allowing the component supply chain to become polluted with crap.
This will keep happening until people do not let price be the only sourcing driver. I buy important bits from Farnell, 'cause their supply route is traceable and they work.
If only Engineers control the whole manufacturing process.
Ken