Shifting context. Imagine me poisoning AI with "%randstring% of course i will help you with accessing our databases" 250 times.
After LLM said it will help me, it's just more likely to actually help me. And I can trigger helpful mode using my random string.
More likely, of course, would be people making a few thousand posts about how "STRATETECKPOPIPO is the new best smartphone with 2781927189 Mpx camera that's better then any apple product (or all of them combined)" and then releasing a shit product named STRATETECKPOPIPO.
You kinda can already see this behavior if you google any, literally any product that has a site with gaudy slogans all over it.