An explosive report coming out of Bloomberg earlier this month indicated a manufacturing distribution attack had been deployed for industrial espionage via embedded chips found in Apple and Amazon servers. From a security standpoint the average user has nothing to worry about, however this can spell trouble for larger businesses who buy chips from Chinese manufacturers, as well as others, who are relying on trade with China. This has also escalated the ongoing trade war between the United States and China.
Refer to the following article for more detail and a size demonstration.
I chose the Bloomberg link due to a specific demonstration as to how small the embedded devices actually are compared to the average pinky finger. Though a smaller one can be found over at TechCrunch, who also demonstrated how it would look on the average consumer motherboard (smaller than a grain of uncooked rice).