Bitcoin thrives on illegal activity.
Once the criminals running these activities get caught the bitcoin scheme will completely collapse.
wow there are many wrong assumptions here...
1) bitcoin does not thrive on illegal activity (eg i didnt do anything illegal with it)
2) not all criminals get caught
3) there will always be new criminals - so it is impossible to catch all
4) bitcoin is not a scheme
5) bitcoin will not collapse
did i miss one?