Nokia has been recently caught violating user privacy: Nokia cell phones route secure https connections via their own servers and decrypt your data while they're at it. This applies at least to their Asha phones, possibly others as well. Nokia justifies this with "optimization". Other cellphone browsers (eg. Opera mini) do the same but only with non-secure plaintext connections.
Opera mini does the same. Encrypted data cannot be compressed. The only (also, very important) difference is that for Opera mini, it is clearly written in the conditions of use.