Scamsters are present everywhere. These are rampant in online frauds. Some of them are active on mobiles.
1.tips providers providing free tips, free trials, sharing profit etc...etc.
2.posing as banks seeking your debit/credit/ATM card number and ipin and one time password.
3.posing as law enforcing authorities like RBI, IT, etc
4.posing as voluntary organisations seeking donations.
Put them in conversation, give all the false information. If they are seeking info in hindi, switch to english. If they speak english switch to Tamil. If they speak Tamil, switch to aliene language (that you donot know, the other person do not know). Let them struggle trying to trap you.