Are you stupid enough to write about your chosen path of joining the militant nationalist crusade? Then yes, you will get in trouble.
It's best to assume a worst case scenario: getting flagged. This can have consequences for your career (especially if you work in the public sector) and family life. If you simply wish to express your support to Breivik, I'd suggest doing so anonymously, by not providing a return address. In this scenario you can be relatively free in how you express yourself in your letter. If you are established, self reliant, and willing to defy the system regardless of the personal consequences, or wish to assist Breivik and engage in non-violent activism then give your full details, and expect a reply.
It's also possible that your letter gets leaked to the press, the chance of this happening is a higher for letters that contain criminal content and have a copy of it given to the police, as more people will have access to it.
Will the Norwegian authorities put me on a black list?
If you include your name and address with your letter you most likely will. Norwegian authorities have made it a priority to deport all foreign militant nationalists that support Breivik and have a criminal record.
It's unclear if the Norwegian authorities will contact your government for writing a letter to Breivik, they most certainly will if they believe it contains unlawful content.
Are you underage?
Then you likely live with your parents and are forced to write from your home address; this is very undesirable. The system loves intimidating minors and might take you in for questioning and / or confiscate your computer. Make sure your computer doesn't have anything on it you'd rather not explain to a police officer, with a little luck you'll get it back in one piece.
It's best to protect your reputation until you are established in the world. Being designated as a far right supporter can affect your future options, both as a professional or as an activist (no indigenous resistance/anti-marxist/anti-islamist organization can afford a link with Breivik at this point). Your parents may face repercussions as well. Instead, focus on increasing your future earning potential and gaining influence, get involved with moderate organizations, or form your own. And of course you can always send an anonymous letter.
Are you a girl or woman that is in love with Breivik?
You should know this is perfectly natural, I encourage you to declare your admiration and love for Breivik. Publicly if possible, especially if you're cute. Men need to know that women admire militant nationalists. The Jihadists have 70 virgins waiting for them, let our guys be confident that they can look forward to having a few female penpals, or even a hot prison wife who will worship and revere them. Writing a run of the mill love-letter is low risk as the authorities will label you as just another emotionally confused female.
Are you a serial-killer fan, an angry life-hating self-mutilator, or want to help him find God?
Feel free to write in your diary instead.
Do I need to include Norwegian return postage?
This will greatly increase your odds of receiving a reply, though it can be tricky to get your hands on Norwegian stamps. All monetary gifts will be confiscated with the exception of stamps.
Yes, Breivik will receive letters that aren't written in Norwegian. It is however best to write your letters in English so Breivik doesn't rely on a potentially erroneous translation by the prison authorities. Breivik in fact suggests to learn English for international correspondence if you don't speak the language.
Use the astral realm of the cultural conservative. Pure ethereal thought energy will transmit mail message.
Will Breivik write me back?
Hopefully! But it takes a long time. Make sure to share the interesting tidbits with the Breivik Report if you do get a reply!
What is the mailing address of the prison that Anders Behring Breivik is in?
Anders Behring Breivik