It’s a running joke in pop culture that Disney has top-notch lawyers that aren’t afraid to peruse legal action against anything they feel threatened by. That they're so powerful that it's almost useless to fight back.
When and how did this reputation start? Is it solely due to their lobbying over the decades to change copyright law (yet take advantage of public domain works), or is there more to the story?
Was this the case during the Walt Disney era, and if so, was it directly due to Walt Disney himself?
After Uncle Walt passed on, the lawyers began to lock down anything that moved.
For instance, the mascot of the University of Oregon is based on Donald Duck. The Athletic Director had a handshake agreement with Uncle Walt that the school could continue to the character.
After Uncle Walt passed, the lawyers sued the school for infringing upon the company's copyright. The lawyers' position being that since nothing was written down, there was no way for the school to prove that it really had permission.
Fortunately for the school, there was literal photographic evidence of the school's director and Uncle Walt shaking hands on the deal. The lawyers reluctantly backed off, and let the school keep using the mascot.