They absolutely prey on people not being having the time/resources to fight back.
A friend in the UK had his deposit withheld as "mail charges" by his landlord upon moving out. Turned out the fine print in his lease said that he wasn't allowed to receive mail at the house he was legally renting.
> his lease said that he wasn't allowed to receive mail at the house he was legally renting.
Pretty sure that is not a stipulation you can legally put in a tenancy contract. Because both parties have to be able to serve notice on the other via post in writing. Same reason you are legally entitled to know the postal address of the landlord.
I'm sure you are right, but that didn't stop the landlord from trying their luck. Your observation about serving notice is on point, because in the end the deposit was returned only after my friend filed a small claims case against them.