Critics of strong encryption are everywhere, but mostly in government agencies and in ignorant facebook posts. They usually go something like this:
Traditional mail (post) has been accessible by law enforcement for centuries and no one bothered about privacy until now.
However, this is a faulty comparison.
When computer scientists explain that strong encryption can not have backdoors that allow government agencies to access encrypted data without the encryption key, this is a completely different kind of "access". The access referred there is in regards of mathematical strength, not of "fairness" or "legality". The encryption algorithm would be weak – and therefore useless – if it had any build-in backdoors.
No one would trust a safe to guard their gold bars if it came with a special keyhole that allows that safe to be opened by governments or the manufacturer. That key system would be exploited. That special key would be stolen. Critical points like that are going to be broken if they are the only impediment against invading the safe. People are only going to trust safes that are (reasonably) impermeable to anything but the mechanism of opening that can only be operated by its owner. Believing anything else is just wishful-thinking.
However, this is not the point of my rambling. There are better articles that do that, like this one from Tech Republic. My point here is that the comparison to physical mail if a faulty one. A fallacy.
Government agencies do have access to physical mail if required by a court. This has been the standard for centuries in some countries, like the UK. It goes in line with governments having access to bank statements and so forth. However, the only reason access to physical mail violates people's privacy is because the post letters are not encrypted. (They're plain text!)
Had you encrypted your letters with a strong algorithm, and sent them via physical post, there would be nothing the government could do to read your letters. They would need the encryption key.
There has never been any laws (to my knowledge) that forbids citizens from manually encrypting their physical letters and sending those by post. And in the same fairness, there should be no laws against that for virtual mail as well.
Do not believe these thought fronts in the name of "security". Do not accept fear-mongering.