EXHIBIT 5.1

                             GREENBERG TRAURIG, LLP
                              The MetLife Building
                          200 Park Avenue, 14th Floor
                               New York, NY 10166

                                                                    June 8, 2001

MonsterDaata, Inc.
32 East 31st Street, Suite 900
New York, New York  10016

Dear Sirs:

            We are acting as counsel to MonsterDaata, Inc., a Delaware
corporation (the "Company"), in connection with the Registration Statement on
Form SB-2, filed on June 8, 2001 (the "Registration Statement"), under the
Securities Act of 1933, as amended (the "Act"), covering 18,567,772 shares of
the Company's common stock, par value $.001 per share (the "Shares"), which are
being registered in connection with the proposed sale of the Shares by the
entities listed as selling shareholders therein.

            We have examined the originals, or certified, conformed or
reproduction copies, of all such records, agreements, instruments and documents
as we have deemed relevant or necessary as the basis for the opinion hereinafter
expressed. In all such examinations, we have assumed the genuineness of all
signatures on originals or certified copies and the conformity to original or
certified copies of all copies submitted to us as conformed or reproduction
copies. As to various questions of fact relevant to such opinion, we have relied
upon, and assumed the accuracy of, certificates and oral or written statements
and other information of or from public officials, officers or representatives
of the Company, and others.

            Based upon the foregoing, we are of the opinion that the Shares have
been, or when issued, delivered and paid for will be, validly issued, fully paid
and non-assessable.

            We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to this firm under the caption
"Legal Opinion" in the Prospectus forming a part of the Registration Statement.

                                                    Very truly yours,


                                                    /s/ Greenberg Traurig, LLP

                                                    GREENBERG TRAURIG, LLP