On the same note, even having picks in some locations may legally be an issue; for example, here's info on laws on a state by state basis in the US:
http://toool.us/laws.html
If you're that concerned though, likely best not even to attend conferences that would be selling picks, since it's easy to track where people go and use network analysis to ID the likely intent of that cluster of people, use public info, info leaked by someone else there, etc.
If you're that concerned though, likely best not even to attend conferences that would be selling picks, since it's easy to track where people go and use network analysis to ID the likely intent of that cluster of people, use public info, info leaked by someone else there, etc.