False-positives are bound to happen with any sort of security software, not matter who you’re hosted with. Unfortunately, it just happened to be us this time.
In this case, AVG received one suspect report and chose to block their customers from all 25 million WordPress.com blogs rather than contact us. There’s nothing that we can do to prevent situations like this, and you may want to consider seeking another security service if they make a habit out of this.
AVG has replied and it was definitely a false-positive on their end.
Users will need to update following this guide to remove the warning: http://www.avg.com/us-en/faq.num-3271