On its front page you'll read this:
"This site has been created for the purpose of providing members of the Canadian and American Reformed Churches with important information concerning the erroneous decisions of General Synods 1992, 2001 and 2004. We focus on the decisions, which established Ecclesiastical Fellowship with the Presbyterian Church of Korea, the Free Church of Scotland, the Orthodox Presbyterian Church, the United Reformed Churches, and the Reformed Church in the United States.
"We are convinced that even though these General Synod decisions have been unsuccessfully appealed, they are in conflict with the Word of God, our confessions and our Church Order. We believe that when consistories accept these decisions as settled and binding, they also accept the practice of an open Lord's Supper, promote the false doctrine of the pluriformity of the church, impair the authority of the office-bearers in maintaining discipline, and undermine confessional membership."
I have bolded what seems to be their primary concern. The mistake of these brothers is in claiming that these churches with whom we have entered into ecclesiastical fellowship hold to the practice of an open Lord's Supper table. These churches do not hold to this practice. They may fence the table in way different from how the Canadian Reformed Churches do, but they fence the table. To say that they hold to an open table is not right.
Even a verbal warning, as is often done in the OPC, is not an open table. When persistent sinners are warned to stay away lest God's judgment break out against them, that's not an open table. We might disagree that it is the best way to fence the table, but it's not an open table. To say so is wrong.