Can I share this videos in my site's blog?
Sure. It will be appreciated if you can give credit in some way, etc. stating "Courtesy of the Israeli Bitcoin Association".
Can I share this videos in my site's blog?
Unless specially stated that you can't record or share it (paid concerts, other art shows, where bootlegs can be illegal); every public meeting is free domain and you can record and share it as much as you like.
Be sure to drop a link to your blog when you will be done. If it is in English I will be happy to see it.
IANAL but I expect there's a difference between recording and sharing on your own, and using a video produced and uploaded by others. In the latter case there should be an option to control on what circumstances it can be used.