Nah, don't worry about it. I think as long as you do not use these software for commercial projects they won't care.
To some extend it's even good for those companies. The more people can use their software, the more will buy their software later for commercial projects.
That's the reason for all these 'learning editions', 'trial editions' and 'free, older versions'.
And all those CGI competitions... it's all for this reason.
I don't say it's ok to dl these software. But those companies aren't evil, or something. They want to earn money. So if you're a poor student, using their expansive software for non-commercial things, I highly doubt they'll have any interessed in you. (Neither good, nor bad.)
Putting potenial customers into jail is not good for buisness.

But you can sure feel better if you own the software you're using.
And there are many free alternatives...
They are like poison to commercial companies. People gow up using this free software, will probably stick to it. And they probably won't buy an expensive software they cannot even use...
I guess will see more 'learning editions 'n stuff" soon.