Recently I introduced Bitcoin and cryptocurrency to my friends and family,they liked the concept but they asked me a question that I wasn't able to answer.Is Bitcoin really secure?What if a hacker was able to hack Bitcoin system/blockchain?Who manages Bitcoin security and what are the security measures taken to avoid hackers being able to steal Bitcoins?Why Bitcoin is not blocked for those who use it illegally by buying/selling in the deepweb market?What if governements ban Bitcoin because of these people?
I really appreciate if you guys give me some answers