is there is any problem in revealing your credit card no & bank acc in internet

You should be very careful about revealing any personal information (due to identity theft). Only reveal bank and credit card information to websites that you trust and when you are on a secure server (the lock sign should show up on the bottom of your screen). There are a lot of thieves out there, so be careful.

There is no problem at all in revealing credit card detail and bank account number. The problem is in revealing ur log in info i.e. ur id and password. Until these two are protected, there is no harm in providing bank account and credit card details. Dont tell ur password and log in id to ur most trustworthy person even.