But what do people do if miners approve a fraudulent withdrawal that steals money from the sidechain? Sztorc's proposal is to engage in a user-ctivated soft fork (UASF) to invalidate the invalid peg-out transaction. This presents a huge risk in terms of consensus to the mainchain. The UASF in 2017 was a high-risk move that only barely succeeded and Bitcoin was much smaller than it is today. The larger Bitcoin grows, the more difficult such actions will be to coordinate.