I don't have a LinkedIn account because I don't think that any social network's management can be trusted over the mid to long term on matters relating to privacy, etc. LinkedIn is better than others so far, but the incentives do not align.
Yet I still get a not insignificant amount of spam connection requests.
Then don't give LinkedIn any information that you wouldn't want becoming public? The tool is just as useful with just your résumé transcribed into their system as it is with that plus a bunch of your secrets.
Yet I still get a not insignificant amount of spam connection requests.