Using secure sites (i.e. with the https, and the little lock symbol) are reasonably safe. The are safe enough even on public wifi. Banks use https. There isn't too much risk to logging onto your bank with your laptop on a public network (I would never use a public laptop to do this, but that is a different issue).
Of course, if you log on to an unsecure site, such as able2know, there are lots of ways for people in the room to get your password. I actually use able2know from public networks because I don't think there is much risk to someone wanting to use my able2know account (they certainly won't make any money). If someone gets my able2know password, no biggie.
Of course this brings up one of the biggest blunders people make on their internet security-- internet passwords.
If your bank password (that is the key to real money) is the same as your able2know password (that is key to messages that aren't worth any money), you are making a real stupid mistake.
For that matter, if you able2know password is the same as your email account password, you are making the same stupid mistake in a little more indirect way. If I have your email account password, I can tell your bank that I am you and the bank will send a password reset message to your email which (since I have your email password) I can receive.
In summary, it is very important that your email password is completely different than you bank password which is completeley different from the passwords you use for anything else (i.e. social media).