https://bitcointalk.org/index.php?action=profile;u=169144 is their profile, including email and Skype username. The phone number isn't publicly listed in their Skype profile (screenshot taken, PM if you want it). That email address isn't attached to a Facebook profile, but it and the Skype username pop up in Google search results; I haven't had time to look at every one to see if they were paired with a phone #.
http://twitter.com/geheimdienst came up in Google, but 1) the Twitter profile pic doesn't appear to be of the same guy in the Skype profile pic 2) it hasn't had any activity for many years, so even if it was the same guy, the Twitter profile was probably last set before moving to NL.
sp33dd34m0n has multiple references in the Skype profile, and Googling that comes up with
https://twitter.com/sp33dd34m0nhttps://www.youtube.com/user/sp33dd34m0n which is part of iOM-Network - German phone number +4916094180956 listed on
https://plus.google.com/111670680921336737718/about - with WHOIS privacy on iom-network.com
http://www.ebay.com/usr/echnaton333 matches their Skype username, but they're no longer an eBay user. In addition to the neg on eBay, there is
this scam accusation on Localbitcoins' forum against geheimdienst in 2013, but it was retracted.
geheimdienst's LB feedback also shows
Jan. 8, 2014, 12:06 p.m.
- Ripped me off after a few successful trades.
Stay away if you don't want to get robbed!
I've asked in Freenode IRC #bitcoin-NL too (see quote below); someone there responded and may reply below or PM you but doesn't want me to tell you their username, because "if that guy wants to do something malicious... he can come after me". I'd appreciate a 50/50 split of the bounty for my referral if contact is made, so please run the successful person's username past me before sending the bounty.
As of this grab, their German phone number was 49 (0) 160 94180956 and email
geheimdienst333@hotmail.com https://web.archive.org/web/20110107025441/http://sp33dd34m0n.net/