Can I help you? On Twitter, the answer is no.

Objective: Determine whether a Bank of America card can be used in all countries, and find out what the foreign transaction fees are.

Twitter: I tweeted @BofA_Help, the bank's six-person Twitter team. About 40 minutes later I got a message saying that the bank's Visa/MasterCard cards would work anywhere that accepts Visa/MasterCard. Easy enough. It got trickier, though, when I tried to find out what the transaction fees were. I was told to Direct Message my phone number and zip code (unclear why that information was necessary), but I couldn't send the message because @BofA_Help wasn't following me. I reminded them to follow, which they did an hour later. After messaging them my information, they publicly tweeted a link to a foreign transaction fee primer on their website.
Time: About two hours
Problem solved: Mostly

Phone: After declining to enter my account number or social security number a few times, I was eventually connected to a representative who was able to give me information on the cards and the transaction fees. It's 3% for Visa and MasterCard, 1% for American Express -- slightly more complete than the information on the website.
Time: Less than 5 minutes
Problem solved? Yes

Website: After being connected almost immediately to a credit card service representative, I was able to quickly get the information on the cards' usage abroad and the fees.
Time: About 3 minutes
Problem solved? Yes

Verdict: Bank of America's verified Twitter account, with its borderline creepy photo of five staffers posing in red polos, seemed promising, and clearly well staffed. It could have been more helpful though, and with many of its tweets directed at users who are badmouthing the company, it comes off as at least as focused on potential social media damage control as it is on solving customer problems. On the bright side, the online live chat was extremely fast and easy to use, and the bank hotline was relatively painless.