But this seems true too for paper-means communication. People panic with the security issue of IT side more just because they have little knowledge about how the data were manipulated inside the mahcines and through the wires.
Drop the hardcore hacker cases first. Today many of the advance CAD-based software builders have developed a second data type for sharing purposes. These light-weight format vs. propriety format help protect the geunie knowledge and methodologies about how the contents were built. Usually they only contain essential data enough for the down-stream user ( e.g. contractor) to do their own work. A very common example is DWF developed by Autodesk.
Some people refer such technology to pdf format of acrobat reader. I would say they are far more "safe" in terms of intellectual property security. pdf format are about graphic and text, which could be easily transformed to other formats by making screenshot and text recognition softwares (many of them bundled with scanners you buy), or simply decoded by ametuer hackers.
In graphical world, potable format files only contain approximate data accuracy (e.g. 0.1mm) - for example, 2 lines are seen joined in a potable format are actually broken lines. Such low-feidility data technology reduce the file size and hinder the data reusability at the same. Design-wise, rule-based or knowledge-based features were also thrown away - for example, the depth-span ratio of a steel beam is optimized for a designer-style staircase. This render the digital data dispatched similar to those in legacy paper era - not better, not worser.
But this is only part of the story, since you have to make sure the data you shared and forming part of BIM is good for the purposes of the whole project team, there are many good chances that they conflict your security policy.
We'll discuss this issue later.