they dont mark you as arbitrage, you're confusing something, accusing someone of arbitrage is a very difficult and unprovable matter, because their sports line is used by many providers and not just betby
This isn't true at all and I am speaking from experience. Multiple sportsbooks usually use a single provider due to which they ended up sharing information with each other without disclosing the details to the public.
If you are identified as an arber at one site, other sites using the same provider could ban you quickly because of their information sharing tactics.