This doesn't change much. I am certain the IMEI wasn't registered when I imported Droid 4s from the USA. I am even more certain the $3 GM Modules I got from Aliexpress have no registered IMEI. So this rule doesn't seem to apply here. And I am happy that the government has to do several more steps to trace my activities by cell towers here. After all I haven't done anything bad.

Also I am quite curious: What happens with tourists who visit?
Do they have to register their phones when entering the country? Do foreign SIMs work regardless of them being in a registered IMEI phone?