Every now and then I get E-Mails (or messages on certain services) from a recruiter. Most of the time, these people are very unlikable.
They act like you have a super interesting profile, even though you don't. They won't look at the work you've done, neither the professional work, nor the open source stuff. They won't care about what you've configured the preferences for your next job to be, they don't care about what you like or dislike. They don't care what city you want to work in, whether you want to work remotely (or in an office, like me) or whether you aren't interested in full-time offers. They don't even care whether you've ignored their previous 20 messages. They also try their hardest to get your telephone number, so they can annoy you every now and then.
At some point, one of them even called my (back then) employer and told them I talked to them about a job change and that we had an appointment, which was simply untrue.
Please give a shit about the people you want to hire :)