Have We Now Gone Back To WWII Censorship?

Just as an aside, I was used to having incoming letters "registered" at the US end of the journey to me, forcing me to sign for them. They were not sent registered by a mid-range military officer in Egypt, but they arrived registered.

When I took over a PO Box in the late 70's and had it for a handful of years, I learned the prior box holder ran some kind of swingers and other reproductive like activity printed newsletter. Take a moment and remember that was pre-internet. I did get interesting collectible mail. Occasionally I'd be a jerk and return the contents under cover with a photocopy of the envelope if collectible but addressed to Mrs/Ms. Smith if sent by a male and Mr. Smith if sent by a female. I also got some routine printed on newsprint (BIG wood chips) magazines offering all sort of NSFW advertisements or worse. I usually dropped them off at the local US Postal Inspector Office and became somewhat known for doing so. One bad, as in clearly not good in a deviant young way, sending received which I again took the the USPIS Office gave me a surprise. The Postal Inspector looked at it, laughed and said, "we probably sent that one."

The fun ended when my work schedule did not allow me to get my mail when access hours and days changed so I took a box in a different post office.

Personally the "Please Do No Fold or Bend" sticker screams there probably is a "PHOTO" inside and NOT drugs.

2nd guessing becomes fact?

An example from Brasil to the US, 2015:

I've had several covers outgoing and incoming to Lebanon that were opened by customs either in Lebanon or the other country.
This is so normal, to the point that sometimes, I have a small corner from the envelope cut off, so that customs can inspect it without opening the whole package (this was recommended to me by a postmaster in Lebanon).
In all cases, the addition to the cover still makes a good postal history item.