If I purchase bitcoins via p2p, can I get some problems if the bitcoins I get were involved in some criminal activity ? If yes then how do I avoid such situation ?
There have been some attempts in the past to try to take the history of your bitcoins into account and to try to blacklist them, so there is not much you can do about it, after all you cannot make a research about those coins on your own before you receive them, so if you are asked about them when using a centralized service you have no other option but to tell the truth and told them that you got your coins by exchanging them in a p2p trade.