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 ?
Yes you should be concerned. That’s one of the problems of a public blockchain. Don’t buy any bitcoins otc imo. It is risky. Police may show up at your door and you may lose both your coins and your FIAT in the end. If you want bitcoins buy it from an exchange. Preferably from a big exchange like coinbase or binance.