The best way to protect yourself is to never disclose your personal details publicly, especially online.
These days, for almost every financial transaction, we share details like our age, PAN, address proof and even bank account details. On the face of it such actions are innocuous; however these are breeding grounds for identity theft. Most often, you will discover the identity theft only later when you find an unauthorised transaction or a payment against purchase of something you did not order.
The best way to protect yourself is to never disclose your personal details publicly, especially online and on social networks. Do not reply to calls seeking details, even if they say it is from your bank. Don’t get carried away with emails from friends stranded on an island asking for money to be transferred to them. Most importantly, whenever you are attaching proof of address and PAN, write the purpose for which you are sharing it on top of the copy to check misuse.