First let's cover the Norway Part...
Just because you are in Norway doesn't give you protection.
In 2007 Norway signed the TRIPS agreement which is comprehensive multilateral agreement on intellectual property. This agreement basically extended the powers of the Berne Convention treaty that established a basic standard of copyright protection.
Norway is covered under the European Unions Copyright Doctrine. You can read more about it here in an article titled "Copyright exceptions for teaching purposes in Europe":
If your video is getting views in the U.S. then technically you are breaking U.S. copyright laws (unless you can prove fair use). It all comes down to whether a company or the government wants to go after you. But different international treaties allow other countries to sue (and/or arrest) copyright infringes in the U.S. and in turns allows the U.S. to go after foreign copyright infringements.
This power is used everyday by adult film companies going after small foreign owned web servers.
Now let's cover Fair Use...
Fair use is tricky. Just because it's an educational site doesn't mean you automatically fall under fair use.
Fair use is in Section 107 of the U.S. Copyright Act. It uses 4 factors to determine fair use. These factors are:
- the purpose and character of the use,
- the nature of the copyrighted work,
- the amount and substantiality of the portion used, and
- the effect of the use on the potential market for or value of the copyrighted work.
Don't fall for bad advice that's all over the internet like "It it's educational it's legal" or "If it's a parady then it's legal." Not all parodies or educational products fall under fair use.
Also, courts in different jurisdictions have ruled opposite of each other for almost the exact same cases of fair use claims.
There are many nuances to Fair Use that only a lawyer can answer after seeing the finished product.
And don't forget that Fair Use won't stop you from getting a cease and desist letter or a lawsuit. It's only a defense. You may have to still prove your case in court and answer like "The content you used, was it the best image/video for your curriculum or did you choose it because it's popular and will increase your sales?", or "Did you use the minimum amount of copyrighted content to make your point, or did you let it run on to get more content into your product?"
Bottom line, it's up to the company that owns the copyright as to whether or not they want to pursue you. For instance, J.K. Rowling let a man run a website that was a Harry Potter Encyclopedia. She even said she liked the site. However when the man tried to turn it into a book, he lawyers came out claiming copyright infringement.
Final piece of advice... Stay away from using Mario Brothers. Nintendo is infamous for going after anyone using their content. They even go after people putting up positive reviews of their games on YouTube. Which is stupid because 90% of gamers make their buying decisions based off of YouTube videos. So Nintendo is suing people giving them free advertising.