Reviewing your credit card statements once a month is too infrequent at this point. With software like Quicken, you can download transactions as often as daily and not only know what the activity is, but also classify them for better budget management. At the very least, one should be accessing their bank/cc web site (from your home machine, not in a hotel or library where key-loggers could be present) weekly or more often to at least check on transactions.