I don't understand how you can run a illegal service and use similiar pseudonyms and @gmail.com or @live.com e-mail addresses. Reminds of these excellent slides

I don't understand how you can run a illegal service and use similiar pseudonyms and @gmail.com or @live.com e-mail addresses. Reminds of these excellent slides for opsec: http://slideshare.net/grugq/opsec-for-hackers http://slideshare.net/grugq/opsec-for-hackers There are similiar services available as tor hidden service where you can pay with bitcoin. But I really don't understand why would anyone use this? Is this some form of blackmailing for buisnesses that need to be online to generate money?