They do sweep and remove some of the old dead shells eventually - just not very often. Seems like every time they do a sweep - more open and go dark after dumping shares
Quote from the SEC
"Once a company ceases its filings and investors no longer have current information about it, there is no good reason for that empty shell to remain exposed in our public markets," said Christopher Ehrman, co-national coordinator of the SEC's microcap fraud working group, said in a statement. "In this initiative, we are committed to identifying unacceptable risks in the marketplace and removing them to safeguard investors."
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