Take note: whatever you place in the Net in the free sites (Facebook, Twitter, Instagram, Google Sites, WordPress.com, YouTube, Slideshare, Scribd, etc), you are being tracked for business purposes (by advertisers) and scam purposes (by hackers).
Make sure you don’t put anything that you don’t like to be tracked, particularly financial matters and other strictly confidential matters. You decide what not to put and to put.
Make sure to protect your free sites with strong passwords so as to prevent hacking. Also, make sure to log out particularly when you use public computers or other people’s computers (safest is not to use public computers or other people’s computers).
A personal advice.