Can I lock the credits not to be touched by other team members ?

Matt, go to the "Team" page on LEED Online and click on "exclusive access". Then only the Team Manager and Administrator have full access to all the credits.

This is correct but I wanted to add a note. There is a real challenge with this (that I understand the LEED Online team is trying to correct) when using CAMPUS. When you register a master site that has multiple building projects on the site, all of the members are listed under MASTER SITE. Although you can restrict access, as Deborah pointed out, you can not restrict the entire team from seeing work on every project. So, in my current situation, there are three architects, seven engineers, several landscape architects, etc. etc. etc. on three distinct projects on the Master Site. Currently there is no way to even mark which project is theirs. As we register more projects under a single Master Site, the challenge is compounded. The recommendation to the LEED Online team is that project team members be assigned under their project on a campus, not under the Master Site "team" and that viewing access be limited to their specific projects PLUS Master Site credits. There is no need for everyone to see every credit on a campus. Professional firms who compete every day are quietly benefiting from viewing others' work/plans/documentation in LEED Online.