The periodic government infatuation with warrantless access to cell phone data is an example. This is mere laziness on the government's part, and utter ignorance of the math traps they create with their stupid ideas.
Proof:Yet another article in favor of this bad idea.
And, of course, well-intentioned people trying to implement it
without realizing that the "secret" to their backdoor is subject to acquisition without mathematical analysis.
Finally, people who think rationally about the problem realize that designing encryption backdoor protocols is giving up privacy with no determinate endpoint, as shown here.