Sure, I used Maltego (commercial version + commercial domaintools access): https://en.wikipedia.org/wiki/Maltego https://en.wikipedia.org/wiki/Maltego (although

Sure, I used Maltego (commercial version + commercial domaintools access): https://en.wikipedia.org/wiki/Maltego https://en.wikipedia.org/wiki/Maltego (although Maltego also has a free version). I love domaintools as it allows to find anything by anything. Like domains (current and historical) by email, or even by fragment of registrant information, such as by phone number or by zip code.