I saw two related posts on TechCrunch this morning that resonated with some of the issues I face in my day job. The post entitled MySpace Nukes SingleStat.us states

Well, so much for the SingleStat.us experiment that allowed people to find out when someone on MySpace changes their relationship status. MySpace’s friendly lawyers sent a cease and desist letter to David Weekly, the engineer who built SingleStat.us, demanding he take the site down and claiming that his "activities are causing and will continue to cause MySpace substantial and irreparable harm."
Something tells me that MySpace might be exaggerating just a bit when they say SingleStat.us is causing them "undue server burden". And if I’ve learned anything from covering companies, it’s that sending a cease and desist letter to a small, one-man startup is generally not going to work out the way you planned.

there is also another post entitled Why is Flickr afraid of Zooomr? which states

Flickr says that users own the the images and tags we enter into their system. Apparently that doesn’t mean they have to make it easy for us to take what we own elsewhere.

When Kristopher Tate, the founder of the feature-rich startup photosharing site Zooomr (see prior coverage), asked Flickr earlier this month for access to their Commercial API, Flickr’s response by email was that "we choose not to support use of the API for sites that are a straight alternative to Flickr." Flickr founder Stewart Butterfield posted to a Flickr forum on Wednesday saying that when it comes to direct competitors like Zooomr, "why should we burn bandwidth and CPU cycles sending stuff directly to their servers?"

The concerns brought up by the MySpace and Flickr folks are concerns that I've had to deal with as our various services such as MSN Spaces and MSN Messenger have grown and we've considered ways to open up these services to third parties via APIs. First of all, despite what Mike Arrington thinks there definitely is a concern when a service shows up whose entire business model is based on polling your website and screenscraping the HTML several times a day. There is a definitley a valid concern if a cottage industry of services springs up around polling MySpace and crawling the various social networks and profiles on the site. Given that there are already necessary evils one has to deal with like search engines and RSS readers, no one who build a successful online service wants to increase the number of web crawlers hitting their site unless absolutely necessary.

However if there are enough of these kinds of requests, it may point to an oppostunity for the website to provide an API. This often ends up building an ecosystem of services and applications aroung the website which ends up benefitting everyone. On the flip side, I often wonder about the balance between making it easy for users to get their data and making it easy for competitors to poach our users. Flickr makes it easy for users to get their data from the service but is hesitant about making it easy for competitors [which includes big players like Google not just startups like Zooomr] from simply bulk copying user information from their service. I think it's a fine line and I've had debates with folks like Mike Torres about where exactly the line is crossed.

In both instances above, the issue isn't the specific incident but the aggregate effect of allowing the behavior to continue.