I have a Western Arms Para Ordnance P1445 (gas blowback) that I use for off-season drills. My racegun is a doublestack Para so I maintain proper grip and feel during practice.
When it came in there were required stickers over the "factory" markings on the gun. These, of course, were removed almost instantly.
Para, Colt, Smith, Ruger and most other companies are not as "anal" and dead set on eradicating all unlicensed Airsoft.
Some airsoft companies like TM, KSC, Marushin and Maruzen, do actually license the trademarks from the respective companies, but not for everything, so that leads to unlicensed replicas.
For example Glock doesn't license ANY replicas. Walther does, but only to Umarex and to Maruzen. Marushin holds the license to most Colts and Rugers and WA licenses Colts, Berettas and Infinity FireArms.
The trick where the vendor hides the trades with tape or some goo, works for most airsoft, but if the package is opened and it contains a Glock or Walther the odds are not good that you'll get it.
This was not as bad a couple of years ago, but now it's a lot worse. In the US, Glock managed to muscle all the airsoft retailers into removing all Glock and look-alikes off their shelves.