OK, OK. I had to jump into the fray. Here's my "shoot-from-the-hip" response. Flame away...
People forget that (with Starbucks) this is a property rights issue, not necessarily a gun rights issue. Property owners can set any policy they'd like, as long as it does not conflict with state or federal law.
If you live in one of the 40 states that issue Concealed Handgun Licenses, how many people carrying guns have you passed by - in the bank, the grocery, Starbucks, the gas station, the library...?
How many times have you been scared by them? Likely never, because you never saw the gun.
By all means, if you are so inclined, please avoid businesses that allow people to carry firearms, just like I avoid businesses that forbid them.
Just for grins, look at this evaluation of the Brady Campaign scorecard of states - and how the states they rank as "good" on gun laws have much higher murder rates than the states that are "bad" on gun laws:
http://blogs.dailymail.com/donsurber/archives/9563 The article has a link to the Brady site where you can compare your own state's "grades."
By the way, you are at least 12 times more likely to die in a car accident on the way to Starbucks than you are to die of a gunshot wound while there. The CDC stats have borne this out pretty consistently over at least the last 10 years.
Please do some honest, impartial research before reacting in a knee-jerk way. This goes for both the "antis" and the "pros" out there. I've seen a few comments from people I'd rather not sit next to.