It is trivial to fingerprint the default configurations that browsers currently ship with, but it isn't very hard to make browsers much more resistant to fingerprinting. There's a lot of unnecessary information leakage in user agent strings that can be dropped. Most of the features that browsers have been adding in recent years as part of their quest to become full-fledged operating systems should be off by default for sites that the user hasn't approved. More than half of the estimated bits of identifying information identified by EFF's Panopticlick tool could be denied to trackers if browsers had better defaults.