So i use wuala...
[...]
Someone use it here?
I don't know if there are Wuala users on Planetpeer. I don't use it.
AFAIK this software is closed source. It's impossible to say who has access (the decryption keys) to your files and what this software is doing in the background. I don't recommend using Wuala for important backups, storing secret files or filesharing of files with "dangerous" content or filenames.
There's a company behind and they want to earn money e.g. by selling storage space (which possibly is located on their servers and on harddisks of other users). Nobody can say if it's the same hoax as with
EarthStation 5, or what happens with the online data when the company stop the business (same as with
DRM music from Onlineshops) and how well they work together with the music and movie industry and other organisations (your country is interested into your data too!)...

Better use something like
Freenet for online storage or encrypt your shared files with well established algorithms/programs (e.g.
GPG).
If "security by obscurity" is an option, then you could encrypt your files with
Schizzors (original-file XOR random-data = encrypted-file; encrypted-file XOR random-data = original-file; Description is in
this Posting; OFFSystem uses a similar principle). The downside: Transfering of data 2x as big as the original file is always needed for recovering the original file (encrypted-file + random-data).
Greetings,
Nemo.