He/she who publishes material through LnuPlay is responsible for any copyright laws that may be applied in that material.
As an author of, for instance, a lecture you have an interest in how that "work" is distributed and used. This "interest" is governed by copyright laws. In the same way it dictates how you may, or may not, use an other authors work or parts there of. It means that you can not use material that other people have created without their clear consent (preferably written). The copyright is in place "by default" -that is to say that a picture on a web page can not be used other than for your personal usage, unless other stated.
The permission to use and distribute copyright protected material can be handed out to others in conjunction with the publishing, and today it has become more and more common to publish your work under the umbrella of Creative Commons License. In that license it clearly states under which conditions the work can be used and spread to others. CC builds on, and clarifies, the Copyright law and as the author you are still the owner of your work. You can read more about Creative commons on their web page https://creativecommons.org
In order to make it easier for teachers to be allowed to use material that is published under other licenses than Creative Commons, the University has a so called Copying treaty with Bonus Copyright Access, which gives the teacher the right to use copyright protected material in hers/his teaching. For example for compendiums or lectures. After the latest edition of this treaty it is now also applicable on material in digital form, such as video, but with certain limitations.
Read more about this treaty here:
Ask for permission!
Another way to get permission to use other peoples material is by contacting the copyright holder (which might be a Publishing company) and ask for their permission. If you ask for permission, please make sure to do so in writing, and ask for a written consent in return, for instance via E-mail. Make sure that it clearly states what can be used and in what way it is allowed to be used (distributed/spread). When using or publishing allowed material you must mark it clearly with the source and with the text "With permission".
If you lack permission, or if you can not find a way to contact the author/copyright holder you simply have to defer from using it or spreading it to a third party.