[jnchapel]

Which includes this paragraph:

"If you are uncomfortable with this research and wish to opt out, please email me with your username, and I'll keep your bookmarks out of the pool. If you have questions, ask me on Twitter or email me privately, and I'll be happy to answer them."

[jarek]

While there's only so much privacy you can technically expect from an operator of a web data storage service, I think being upset about an opt-out study - announced only via blog and twitter - that would benefit the operator personally and users almost not at all isn't really unreasonable.

Edit after downvote: I use Pinboard and like it, think Maciej is a fantastic guy, and don't personally have problems with this study, but come on guys. He'll be alright with some dissent.