Microsoft, Apple and Twitter mistakes — five things to know today by Ben Geier @FortuneMagazine July 22, 2014, 8:07 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Hello friends and Fortune readers.Did you know that this year marks the 75th anniversary of Batman? That fact, and many other things nerdy will be celebrated at the San Diego Comic-Con starting later this week, so be sure to check that out if you want semi-spoilers for all your favorite shows. Also nerdy: A raft of tech sector earnings due later today. Here are five things you need to know in business news today.1. Big guns come out on tech earnings.As earnings continue to roll in, two of the biggest tech companies in the world report today after the close of trading: Apple and Microsoft. It is an interesting time for both of them: Microsoft announced the biggest layoffs in its history last week, while Apple is busy preparing for yet another mammoth iPhone launch (more on that below!).2. Existing home sales are out today.We’ll find out later today how the market for selling existing homes did last month. Experts expect an increase of 2% year-over-year.3. Apple places biggest-ever iPhone order.Hold on to your hats, the iPhone mammoth is charging out of Cupertino later today, and it’ll stomp all over any other news. The Wall Street Journal reports that Apple has placed its biggest-ever iPhone order with its manufacturers, and that the new version of the phone will indeed come in both 4.7 and 5.5 inch versions. Start lining up outside your nearest Apple Store.4. Is Bill Ackman hosting a live execution of Herbalife?That’s kind of the way he’s making it seem. The hedge fund guru from Pershing Square is holding a 10 a.m. ET press conference where he promises to detail an “incredible fraud” at the nutrition products maker. He’s not shared any details yet on just what that is, so I guess we’ll have to tune in.5. Note to companies and government agencies: Don’t let interns run your Twitter accounts.Look, I’m not offering any judgment on someone who plays the Kim Kardashian iPhone game. Posting your status on a government Twitter account, though, probably isn’t the best idea. That’s what happened to the EPA Water account last night. The tweet was eventually deleted, but the damage was done. And this is only a C-list celebrity, so its not even like it was something worth bragging about.