Group's history enforcing trademark raises free speech concerns
Goal: Help consumers discern source of information of real estate websites
Operator of MLS.com opposes application by group of 54 MLSs
ICANN may not approve new 'top level' domains before 2012
34 MLSs with 503,000 subscribers on board
MLSs don't expect to submit application to Internet agency this year
16 MLSs backing effort to obtain ICANN approval
Nonprofit plans to unite group of MLSs for effort