I don't mean to be argumentative but I also went through this entire process with a lawyer while drafting my lease and discussing security deposits. There is nothing on the page you referenced, nor in any of the legislature I've come across, nor anything that was mentioned by my attorney regarding a "security deposit account." The deposit only needs to be held in a separate, interest bearing account in a Massachusetts bank. There are then separate laws governing the lease and informing the tenant of said account. I have never heard of any state requiring a court order to withdraw funds from a security deposit, and it seems you're also finding it difficult to find this as well aside from what some judge explained to you at some point before.

I'm honestly not sure what you're referring to. In the state of Massachusetts, there are very specific laws outlining security deposits and none of them specify that a security deposit be held in an account that cannot be accessed by the landlord. Similarly, I do not know what piece of legislature you feel mandates court approval to deduct anything from the security deposit.

Yeah, I am in Massachusetts.

The landlord could take the deposit to cover reasonable damages incurred. If it's included in the lease that the tenant isn't allowed to hang anything and they do, then the landlord could presumably take this from the security deposit. If the tenant feels this is unfair, the onus would be on them to take the landlord to court (which, even at 3x the damages seems unlikely), at which time I would suspect the landlord would point to the language in the lease.

I agree with your point, though. OP should definitely create a paper trail requesting to install curtains/that curtains be installed at the tenant's cost.

My suggestion would be to ask the landlord if you can install a curtain rod. If they're uncomfortable with this, you can ask them if they would mind installing it for you. I have this same language in my lease, but I'd be more than happy to oblige on an as-needed basis. The reason I have this language to begin with is because everyone is different and I've seen some people do some crazy things with nails, screws, bolts, etc. If the landlord is disagreeable in both cases, they wouldn't be the type of landlord I'd appreciate having anyways and at that point I might consider then installing them anyways and assuming the cost of them deducting it from the security deposit and repairing it, especially if you plan on staying long-term.