Cool, i remember these days as well. Indeed it very much looked like StudiVZ just used FBs css filed and changed some colors.. It was a typical german clone success story. Dariani did a lot of questionable things but sold in the right time before the downfall of VZ.

I didnt really like it, they basically did nothing in terms of innovation that FB did, it had the same features for years. Later they had a half-assed app platform that never really took off. It was just a blatant rip-off like so many german startups, sadly.