For someone like me who deals with storage and retrieval contract/pricing/credit card transaction/HIPAA (medical)/personnel files..... I get a chuckle out of this thread.
It doesn't matter what type of network you're on, if you're using a modern web browser and are communicating with your bank site over a secure connection (padlock) for online banking/purchases etc... It is safe. The entire transaction (end to end) is encrypted and safe. The silly wifi password and local router security has NOTHING to do with ensuring the safety of the transaction between you and the bank/vendor.
Now this is not to say that your computer hasn't been infected by visiting (ahem not so nice) websites. If someone infects your PC/Mac, then nothing you do on it is safe - your files are at risk; everything you potentially type is collected.... And again, this is irrelevant for the type of network you are on... If you're infected the traffic goes from your pc/mac OUT to the recipient... Not the other way around. Keep your 14 year old grandson away from your PC and stay away from porn sites; ignore unsolicited emails; keep a good anti-virus product up to date and generally you'll be fine.
It's clear a few of the posters in this thread have no clue what they are talking about. Two people in any conversation know which one between the two of them is making it up as they go along. The maker-upper; and the person who actually understands the subject matter.