First of all, thank you for taking my questions seriously, and thank you for discussing it with me.

They may cooperate, or they may not.
May be the system administrator who works for carrier may want to know something about me. May be friend of him.

As I said I don't believe I am too important person, I just care about security to some extent.
I don't think I worth to set bugs in my apartment, I don't think someone is out to get me - just would like to minimize possibilities of data interception to be on the safe side.
Who uses telnet if there is ssh?

What I want is not to use telnet when there are safer ways.
I don't expect to be %100 safe.
I try to not do things which are %100 unsafe.

However what I send and receive is encrypted. Yes I understand what you've said about why it may not be enough. I know if I use my own email server - then I can only be sure that connection between my client and my server is secure, and I know that I have configured it to send email unencrypted if encrypted connection to other email server fails. I know that if I use some provider's email service like google's then google may, or may not, share this information with some other parties. I am asking here on maemo forums because I would like to discuss mobile specific security issues. And I have mentioned that I don't use sms messaging or voice communication which means I don't give unencrypted data right in the hands of carriers (like I don't use telnet) and in the same time I know that using encrypted xmpp connection does not guarantee a complete safety of communication.
What I question is for example - is using Nokia conversations (it is non-free software, right?) less secure than using Maemo Pidgin port? Is it probable that Conversations have a feature to send data to the carrier before encrypting it and sending to xmpp server?
I wonder what do we know and what we don't about staff like this.

I don't consider RMS's approaches to be extreme (:
Okay - so this is also what I would like to understand clearly - does tablet mode indeed turn n900 into a small laptop with Linux?
We had just NITs before - without GSM/UMTS so can we consider n900 in tablet mode is as safe as Linux laptop, or as safe as N810 in terms of what carrier can know about you?
Does enabling tablet mode mean that carrier cannot get my location? Does enabling offline mode?
So if I connect to wifi - there is no much difference if I connect with laptop or n900. But if I use cell towers in order to get connection then carriers can get my data.
That's why I was talking not about security in general, but about security by using GSM/UMTS and about Maemo/MeeGo operating systems.
What do we know about GSM?
We know that carrier can track my location.
Okay, then when they can do that? How can I prevent it, and does tablet mode prevent it?
What do we know about Maemo/MeeGo? We know that both Fremantle and Harmattan contain non free software and free software.
Which parts are non-free? As far as I know this are GSM chip driver, GPS chip driver, GSM chip firmware. And as far as I know the same non-free software is used in Nemomobile hardware adaptations. So does this mean that we have the same security threats when using Nemo vs using Maemo?
So if we don't use free GSM firmware and drivers we don't know what can do carrier. And I wonder, what does this tablet mode, and this offline mode? What can do carrier when n900 is in tablet mode? Does it take the GSM chip to sleep mode? How GSM chip gets out of this mode? By signal from the board or by radio signal?
Can the carrier get stream from microphone when the tablet mode is used or when the phone is in offline mode?