Simple Examples:
* The disease was insidious, spreading slowly without any obvious symptoms.
* The rumors about the company's financial troubles were insidious, slowly eroding public trust.
* His charm was insidious, making people underestimate his true intentions.
More Complex Examples:
* The politician's insidious propaganda targeted vulnerable groups, sowing seeds of doubt and fear.
* The insidious effects of climate change are becoming increasingly apparent, impacting ecosystems and human health.
* The insidious nature of online misinformation can be difficult to combat, as it spreads quickly and easily through social media.
Using "insidious" to describe a person:
* He was an insidious manipulator, twisting words and playing on people's emotions to get what he wanted.
* The villain's insidious plan involved slowly undermining the hero's reputation and turning his friends against him.
Remember that "insidious" implies something that is harmful, dangerous, and often difficult to detect or understand. Choose your examples carefully to reflect the subtle but dangerous nature of the word.