If you are working with developing something yourself, then you can certainly understand the aggrevation that comes from somebody just ripping your intellectual know how without paying anything for it.
Siemens license policy is actually very fair.
You have the trial license.
If you expire that you can work on, but with some nagscreens. If you cant live with the nagscreens then maybe your work with the software is not so "occasional" - eh ?
The worst that can happen is that so many people circumvent the regular copy protection or trial timeout that Siemens decide to use a much more strict system.
There are hardware locks, and there are licenses that are locked to a particular PC. I would hate if it came to that.