]I would disagree with this, provided however that you independently encrypt the data you have on a cloud service, and keep the decryption keys exclusively stored locally. This is especially true in the context of border crossings. In general, you are going to be subject to having electronic devices searched at every border crossing throughout the world, and as the OP points out, in some cases you may be compelled to give up passwords and decryption keys to files stored locally. However, in general (as is the case in the US), your cloud data is not subject to search when you cross boarders.
Congress Passes CLOUD Act Governing Cross-Border Law Enforcement Access to Data That law gives law enforcement access to information stored in the Cloud that is stored overseas upon possession of a search warrant. This basically means you cannot hide private information overseas in the cloud. However, importantly, this law (nor any other law that I am aware of) allows a cloud account to be searched when its owner crosses a border.
If there is probable cause, and law enforcement is able to obtain a warrant for data, the fact the data is in the cloud is not going to affect law enforcement's ability to obtain said information.