We aThe obvious answer to this question is “No.” However, there are things that can be done that will tend to protect the quality of your collaborative work.
Peer Review. Have an easy to use way of allowing peer review to happen, and encourage it as you bring on those who would help. If you do not make sure both happen than peer review will likely not be a frequent help to your work.
Editorial Review. With or without peer review, every project should probably have at least one editor that oversees changes made to the project’s data. In some cases this would be too time consuming of a task for one individual, so a number of editors may need to be assigned to the project.
Restrict Participation. Though the data would be free to all, sometimes it will be necessary to restrict participation on the data collection task. Some tasks will require too much training to expect from the average user, and in such cases the manager of a project can decrease the likelihood of bad data from entering into the dataset by restricting the ability to change the data to only those qualified. For example, having a group of first year Greek students markup some text with Strong’s numbering scheme would probably be an acceptable way of doing things if there is at least peer or editorial review. However, allowing those same students to do syntactical markup, even with peer and editorial review, would probably be a bad idea.
Because of the nature of the task it would be tempting to not be very restrictive concerning participation just because the use of the data itself is not restricted. But there are several reasons, other than what was given above, to sometimes restrict data entry. First, as the difficulty of the project increases, the chance that the average user can separate the good from the bad decreases. And at that point you have to ask if the project is truly beneficial to the biblical studies community. Second, the higher the skill level of the potential worker, the higher likelihood that this same potential worker might avoid the project because of the previous issue. If you are a highly trained textual critic, why spend a major portion of your time doing work that will ultimately be drowned out by massive amounts of work done by unqualified individuals?
But there is at least one potential problem. If your requirements are too restrictive then no one may participate. You must strike the balance between judiciously strict and naively unrestrictive.
Also related is the issue of the approach of the project. Let us take syntactical tagging of Greek text as an example. Is the tagging going to revolve around one tagging system? And are you working on a sentence level, or on a broader discourse level? Or do you want to cover all your bases and devise a way for every syntactical system to coexist together?. These are decisions that need to be made early in the process and need to be publicized for potential volunteers.
How participation would be restricted would need to be decided on a case-by-case basis. But, in general, a good rule of thumb might be to restrict participation more tightly as the difficulty level of the subject rises.