Do not shoot and cause uneasiness to other people. As long as you do that, regardless whether you are legally ok to do or not, it doesn't matter, you already failed the moral code of street photography.
Most street photos are just worthless snap shots. Don't even deserve an upload to the PC, much less to say upload to flickr or clubsnap.
Only a very low number deserve to be framed.
Out of 10 thousand street photos, less than one get printed. Thats the hard truth.