Feeds are being touted as the best form of syndication everywhere – blogs, email lists, news sites – and for good reason. Feeds are convenient and increase productivity. However, today they are also the possible source of attack on your computer. Suddenly, the role of feed readers gets more complex, they not only have to just read feeds, but possibly look for malicious code and even strip out the invalid markup. Like Nial Kennedy says, the danger is not only the first time you subscribe to a feed. It is quite possible that the blog gets owned by someone else in the future, who might not be trustworthy. Feed readers should also be able to raise this and provide an option for unsubscribing.
We cannot stop using feeds because these attacks are possible. Just like we have not stopped using the Internet because of certain malicious sites. We will continue to be more alert and worried though, everytime an article pops out of a feed, with an increased level of security alert.