Nope...however, to be successful, you do need to meet their special needs:
First, do yourself a HUGE favor and get TRUE CB stock from a reputable breeder. If the person/place can't tell you the species they offer, pass them up, as the SH are likely poor quality pen-raised SH being passed off a CB (these are often called TR).
They must have access to food (frozen mysis or live pods) every day. They lack a true stomach and cannot store food for digestion. This also means that you'll need somebody trained to feed them during vacations.
They must be kept cool...< 74*F for tropical species.
They can't be kept with boisterous tankmates or those who would compete for food.
They can't be kept with anything that stings...certain corals, 'nems, etc.
Flow is fine, as long as it's done creatively...don't plaster them against the wall.
These are probably the most common mistakes peeps make...I'm not being negative, but you do need to know what you're in for.